Glossary of Geology "A"

a

a. Symbol in structural petrology for the direction of tectonic transport,
similar to the direction in which cards might slide over one another.
Striations in a slickensided surface are parallel to direction a.
AGI
b. A crystallographic axis: In the isometric system each axis is
designated a; in hexagonal, tetragonal, and trigonal systems the nonunique
axes are a; in the orthorhombic system a is always shorter than b with c
either the longest or the shortest axis; in the monoclinic and triclinic
systems a may be determined by one of several conventions.




aa

A Hawaiian term for lava consisting of a rough assemblage of clinkerlike
scoriaceous masses. It is contrasted with pahoehoe used to designate the
smoother flows. Pron. ah-ah. Fay; Hess




a axis

a. One of the three crystallographic axes used as reference in crystal
description. It is oriented horizontally, front to back.
b. One of the three reference axes used in describing a rock fabric
possessing monoclinic symmetry, such as progressive simple shear. The a
axis is the direction of tectonic transport, i.e., the direction of shear.
Syn:a direction
CF:b axis; c axis.




abandoned mine

See:abandoned workings




abandoned workings

Excavations, either caved or sealed, that are deserted and in which
further mining is not intended and open workings that are not ventilated
and inspected regularly. Syn:abandoned mine
Federal Mine Safety




abandonment

Abandonment of a mining claim may be by failure to perform work, by
conveyance, by absence, and by lapse of time. The abandonment of a mining
claim is a question of intent. To constitute an abandonment of a mining
claim, there must be a going away and a relinquishment of rights, with the
intention never to return and with a voluntary and independent purpose to
surrender the location or claim to the next comer. CF:forfeiture




Abbe jar

In mineral processing, a porcelain jar used for laboratory batch grinding
tests in ceramic ware. Pryor, 1




Abbe refractometer

An instrument to determine the index of refraction of a liquid between two
high-index glass prisms. CF:refractometer




Abbe theory

The visibility of an object under the microscope is directly proportional
to the wavelength of light, and inversely to the aperture of lens.
Pryor, 3




Abbe tube mill

A gear-driven tube mill supported on a pair of riding rings and
distinguished by an Archimedes spiral, through which the ore is fed and
discharged. Grinding is effected by flint pebbles fed into the mill.
See also:ball mill




ABC system

A method of seismic surveying by which the effect of irregular weathering
thickness may be determined by a simple calculation from reciprocal
placement of shotholes and seismometers. The method was originally used to
solve refraction problems arising from irregularities in the top of the
high-velocity layer. AGI




Abel's reagent

Etching agent consisting of 10% chromium trioxide in water. Used in the
analysis of carbon steels. Bennett




abernathyite

A tetragonal mineral, K(UO2 )(AsO4 ).4H2 O ; in small
yellow crystals; in the Temple Mountains, UT.




aberration

a. The failure of a lens or mirror to bring the light rays to the same
focus. When aberration is due to the form of the lens or mirror, it is
called spherical aberration. When due to the different refrangibility of
light of different colors, it is called chromatic aberration. When present
in magnifiers it often causes inaccurate decisions as to flawlessness or
color of gems.
b. Distortion produced by a lens. It is spherical if a flat image appears
closer to the viewer in the middle than toward the edges of the field of
view. It is chromatic if the visible spectrum is spread to give both a red
and a blue image. CF:achromatic; aplanatic lens; aplanachromatic lens.
See also:chromatic aberration




abime

A large, steep-sided vertical shaft opening at the surface of the ground.
AGI




ablation breccia

See:solution breccia




A.B. Meco-Moore

A bulky machine that cuts a deep web of coal up to 6 ft (1.8 m) and is
used in cyclic mining in medium to thick seams. It runs on the floor of
the seam and does not require a prop-free front. It carries two horizontal
jibs, one cutting at floor level and the other at a height depending on
seam conditions. Nelson




Abney level

A surveying instrument for taking levels up steep slopes; also used as a
clinometer. Hammond




abnormal place

A working place in a coal mine with adverse geological or other conditions
and in which the miner is unable to earn a wage, based on the pricelist,
equal to or above the minimum wage. A term generally associated with
stalls or pillar methods of working. Nelson




abraser

A device for assessing the wear resistance of surfaces. The specimen to be
tested is rubbed alternately by the flat faces of two weighted abrasive
wheels that revolve in opposite directions through frictional contact with
the specimen and exert a combined abrasive, compressive, and twisting
action twice in each revolution of the specimen holder. Osborne

abrasion

a. The mechanical wearing away of rock surfaces by friction and impact of
rock particles transported by wind, ice, waves, running water, or gravity.
Syn:corrasion
b. The wearing away of diamonds, drill-bit matrices, and drill-stem
equipment by frictional contact with the rock material penetrated or by
contact with the cuttings produced by the action of the drill bit in
drilling a borehole. Long




abrasion hardness

Hardness expressed in quantitative terms or numbers indicating the degree
to which a substance resists being worn away by frictional contact with an
abrasive material, such as silica or carborundum grits. Also called
abrasion resistance; wear resistance. Long




abrasion index

The percentage of a specially prepared 3-in by 2-in (76-mm by 51-mm)
sample of coke remaining on a 1/8-in (3.2-mm) mesh British Standards test
sieve after the sample of coke has been subjected to a standardized
abrasion procedure in a rotating drum. BS, 1




abrasive

a. Any natural or artificial substance suitable for grinding, polishing,
cutting, or scouring. Natural abrasives include diamond, emery, garnet,
silica sand, diatomite, and pumice; manufactured abrasives include esp.,
silicon carbide, fused alumina, and boron nitride. AGI
b. Tending to abrade or wear away. AGI




abrasive blasting respirator

A respirator designed to protect the wearer from inhalation or impact of,
and abrasion by, materials used or generated in abrasive blasting.
ANSI




abrasive formation

A rock consisting of small, hard, sharp-cornered, angular fragments, or a
rock, the cuttings from which, produced by the action of a drill bit, are
hard, sharp-cornered, angular grains, which grind away or abrade the metal
on bits and drill-stem equipment at a rapid rate. Syn:abrasive ground
Long




abrasive ground

See:abrasive formation




abrasive hardness test

Test employing a rotating abrasive wheel or plate against which specimens
are held. The specimens are abraded for a given number of revolutions, and
the weight of material lost is a measure of the abrasive hardness.
Lewis




abraum salts

See:abraumsalze




abraumsalze

Ger. Mixed sulfates and chlorides of potassium, sodium, and magnesium
overlying the rock salt in the Stassfurt salt deposits.
Syn:abraum salts; stripping salt. Holmes, 2




abriachanite

An earthy, amorphous variety of crocidolite asbestos. Dana, 1




absolute

a. In chemistry, free from impurity or admixture. Hess
b. In physics, not dependent on any arbitrary standard. Hess
c. Frequently used in the trades to indicate a thing as being perfect or
exact. Abbrev. abs. Crispin




absolute age

The geologic age of a fossil organism, rock, or geologic feature or event
given in units of time, usually years. Commonly used as a syn. of isotopic
age or radiometric age, but may also refer to ages obtained from tree
rings, varves, etc. Term is now in disfavor as it implies a certainty or
exactness that may not be possible by present dating methods; i.e., two
absolute ages for the same pluton may disagree by hundreds of millions of
years. CF:relative age




absolute atmosphere

An absolute unit of pressure equal to 1 million times the pressure
produced on 1 cm2 by the force of 1 dyn. Fay




absolute bulk strength

A measure of available energy per unit volume of explosive.
Syn:bulk strength




absolute chronology

Geochronology in which the time-order is based on absolute age, usually
measured in years by radiometric dating, rather than on superposition
and/or fossil content as in relative chronology. AGI




absolute daily range

During the 24 h of the day the difference between the maximum easterly and
maximum westerly values of the magnetic declination at any point.
Mason




absolute humidity

The content of water vapor in air, expressed as the mass of water per unit
volume of air. CF:relative humidity




absolute isohypse

A line that has the properties of both constant pressure and constant
height above mean sea level. Therefore, it can be any contour line on a
constant-pressure chart, or any isobar on a constant-height chart.
Hunt




absolute ownership

In law, an unqualified title to property and the unquestioned right to
immediate and unconditional possession thereof. Applies to mining claims
and properties. Standard, 2; Hess




absolute permeability

A measure of possible flow of a standard liquid under fixed conditions
through a porous medium when there is no reaction between the liquid and
the solids. This measure is arbitrarily taken for isothermal viscous flow.
It can be duplicated with gases if tests are so conducted that
extrapolation to infinite pressure can be made; specific permeability.
Hess


absolute potential

True potential difference between a metal and the solution in which it is
immersed. Pryor, 3




absolute pressure

a. Total pressure at a point in a fluid equaling the sum of the gage
pressure and the atmospheric pressure. Webster 3rd
b. Pressure measured with respect to zero pressure, in units of force per
unit of area. CTD




absolute roof

The entire mass of strata overlying a coal seam or a subsurface point of
reference. See also:nether roof




absolute scale

See:Kelvin temperature scale




absolute temperature

Temperature reckoned from absolute zero. See also:temperature
Handbook of Chemistry and Physics, 2




absolute time

Geologic time measured in terms of years by radioactive decay of elements.
CF:relative time




absolute viscosity

See:viscosity coefficient




absolute weight strength

A measure of available energy per gram of explosive.
Syn:weight strength




absolute zero

The temperature at which a gas would show no pressure if the general law
for gases would hold for all temperatures. It is equal to -273.16 degrees
C or -459 degrees F. CF:temperature
Handbook of Chemistry and Physics, 2




absorbed water

Water held mechanically in a soil mass and having physical properties not
substantially different from those of ordinary water at the same
temperature and pressure. ASCE




absorbent formation

A rock or rock material, which, by virtue of its dryness, porosity, or
permeability, has the ability to drink in or suck up a drilling liquid, as
a sponge absorbs water. Syn:absorbent ground




absorbent ground

See:absorbent formation




absorbents

Substances, such as wood meal and wheat flour, that are forms of low
explosive when mixed with metallic nitrates and tend to reduce the
blasting power of the explosives, making them suitable for coal blasting.
Cooper




absorber

a. An apparatus in which gases are brought into intimate contact with an
extended surface of an absorbing fluid so that they enter rapidly into
solution. Hess
b. The resistance and capacitance in series that is placed across a break
in an electrical circuit in order to damp any possible oscillatory circuit
and would tend to maintain an arc or spark when a current is interrupted.
Syn:spark absorber
c. Any material that absorbs or stops ionizing radiation, such as
neutrons, gamma rays, alpha particles, and beta particles. Lyman




absorptiometer

A device for measuring the solubility of a gas in a liquid.
Bennett




absorption

a. The phenomenon observed when a pleochroic mineral is rotated in plane
polarized light. In certain positions, the mineral is darker than in
others, owing to the absorption of light.
b. In hydrology, a term applied to the entrance of surface water into the
lithosphere by all methods. AGI
c. The reduction of light intensity in transmission through an absorbing
substance or in reflection from a surface. In crystals, the absorption may
vary with the wavelength and with the electric vector of the transmitted
light with respect to crystallographic directions.
d. Any mechanism by which energy, e.g., electromagnetic or seismic, is
converted into heat.
e. Taking up, assimilation, or incorporation, e.g., of liquids in solids
or of gases in liquids. CF:adsorption
f. The entrance of surface water into the lithosphere by any method.




absorption hygrometer

A type of hygrometer with which the water vapor content of the atmosphere
is measured by means of the absorption of vapor by a hygroscopic chemical.
The amount of vapor absorbed may be determined in an absolute manner by
weighing the hygroscopic material, or in a nonabsolute manner by measuring
a physical property of the substance that varies with the amount of water
vapor absorbed. The lithium chloride humidity strip and carbon-film
hygrometer element are examples of the latter. Hunt




absorption loss

a. The loss of water occurring during initial filling of a reservoir in
wetting rocks and soil. Hammond
b. That part of the transmission loss due to dissipation or the conversion
of sound energy into some other form of energy, usually heat. This
conversion may take place within the medium itself or upon a reflection at
one of its boundaries. Hy




absorption rate

a. The rate, expressed in quantitative terms, at which a liquid, such as a
drilling circulation medium, is absorbed by the rocks or rock materials
penetrated by the drill bit. Long
b. The amount of water absorbed when a brick is partially immersed for 1
min; usually expressed either in grams or ounces per minute. Also called
suction rate; initial rate of absorption. ACSG, 1




absorption spectra

Specific wavelengths of electromagnetic radiation have precisely the
energy to cause atomic or molecular transitions in substances they are
passing through; their removal from the incident radiation produces
reductions in intensity of those wavelengths, or absorption spectra,
characteristic of the substance under study. CF:emission spectra




absorption spectrum

The array of absorption bands or lines seen when a continuous spectrum is
transmitted through a selectively absorbing medium. AGI


absorption tower

A tower in which a liquid absorbs a gas.




abundant vitrain

A field term denoting, in accordance with an arbitrary scale established
for use in describing banded coal, a frequency of occurrence of vitrain
bands comprising 30% to 60% of the total coal layer.
CF:dominant vitrain; moderate vitrain; sparse vitrain. AGI




abutment

A surface or mass provided to withstand thrust, for example, the end
supports of an arch or bridge. In coal mining, (1) the weight of the rocks
above a narrow roadway is transferred to the solid coal along the sides,
which act as abutments of the arch of strata spanning the roadway; and (2)
the weight of the rocks over a longwall face is transferred to the front
abutment (the solid coal ahead of the face) and the back abutment (the
settled packs behind the face). See also:overarching weight;
pressure arch; load transfer. Syn:arch structure




abutment load

In underground mining, the weight of rock above an excavation that has
been transferred to the adjoining walls. Pryor, 3




abutment pillars

Pillars intended to support vertical load in excess of the weight of the
strata directly above them. Generally, these abutment pillars are large
pillars adjacent to smaller pillars, sometimes called yield pillars, which
are incapable of carrying the weight of the strata above them.
SME, 1




abysmal

See:abyssal




abysmal sea

That part of the sea occupying the ocean basins proper. Fay




abyss

a. A very deep, unfathomable place. The term is used to refer to a
particularly deep part of the ocean, or to any part below 3,000 fathoms
(18,000 ft or 5.5 km). Hunt
b. Syn:pit; pot; pothole; chasm; shaft.




abyssal

a. Pertaining to an igneous intrusion that occurs at considerable depth,
or to the resulting rock; plutonic. CF:hypabyssal
b. Pertaining to the ocean environment or depth zone of 500 fathoms (3,000
ft or 915 m) or deeper; also, pertaining to the organisms of that
environment. AGI
c. Of, or pertaining to, deep within the Earth, the oceanic deeps below
1,000 fathoms (6,000 ft or 1.83 km), or great depths of seas or lakes
where light is absent. See also:plutonic
d. In oceanography, relating to the greatest depths of the ocean; relating
to the abyssal realm. Syn:abysmal




abyssal deposit

A deposit of the deep sea, accumulating in depths of more than 1,500
fathoms (9,000 ft or 2.7 km) of water; these deposits comprise the organic
oozes, various muds, and red clay of the deepest regions. CTD




abyssal injection

The process by which magmas, originating at considerable depths, are
considered to have been driven up through deep-seated contraction
fissures.




abyssal plain

An area of the ocean floor with a slope of less than 1 in 1,000 or flat,
nearly level areas that occupy the deepest portions of many ocean basins.
Schieferdecker




abyssal realm

The deep waters of the ocean below 1,000 fathoms or 6,000 ft (1.83 km).




abyssal theory

A theory of mineral-deposit formation involving the separation and sinking
of ore minerals below a silicate shell during the cooling of the Earth
from a liquid stage, followed by their transport to and deposition in the
crust as it was fractured (Shand, 1947). Modern thought ascribes more
complex origins to mineral deposits. AGI




abyssal zone

The marine-life zone of the deep sea embracing the water and bottom below
a depth of 6,000 ft (1.83 km). Stokes




abyssobenthic

Relating to that part of the abyssal realm that includes the ocean floor;
pertaining to or living on the ocean floor at great depths. CTD




abyssolith

See:batholith




abyssopelagic

a. Relating to that part of the abyssal realm that excludes the ocean
floor; floating in the depths of the ocean. CTD
b. Pertaining to that portion of the deep waters of the ocean that lie
below depths of 6,000 ft (1.83 km). AGI




acanthite

A monoclinic mineral, 4[Ag2 S] ; dimorphous with argentite,
pseudohexagonal, in slender prisms; sp gr, 7.2 to 7.3; a source of silver.




accelerated weathering test

A test to indicate the effect of weather on coal, in which the coal is
alternately exposed to freezing, wetting, warming, and light; the
alternation may be varied to suit. This test may be applied to other
bituminous materials. Hess




accelerator

a. A machine that accelerates electrically charged atomic particles, such
as electrons, protons, deuterons, and alpha particles, to high velocities.
Lyman
b. A substance added to increase the rate of a chemical reaction.
Nelson


accelerometer

A seismometer with response linearly proportional to the acceleration of
earth materials with which it is in contact. AGI




accented contour

See:index contour




acceptor

A charge of explosives or blasting agent receiving an impulse from an
exploding donor charge. Syn:receptor




accessory

a. Applied to minerals occurring in small quantities in a rock. The
presence or absence of these minor minerals does not affect the
classification or the naming of the rock. Holmes, 2
b. Fragments derived from previously solidified volcanic rocks of related
origin; i.e., the debris of earlier lavas and pyroclastic rocks from the
same cone. See also:accessory mineral
c. Said of pyroclastics that are formed from fragments of the volcanic
cone or earlier lavas; it is part of a classification of volcanic ejecta
based on mode of origin, and is equivalent to resurgent ejecta.
CF:auxiliary




accessory element

See:trace element




accessory mineral

Any mineral the presence of which is not essential to the classification
of the rock. Accessory minerals generally occur in minor amounts; in
sedimentary rocks they are mostly heavy minerals. CF:essential mineral
Syn:accessory




accessory plate

a. The quartz wedge inserted in the microscope substage above the
polarizer in order to estimate birefringence and to determine optical sign
of uniaxial minerals. CF:quartz wedge
b. The selenite plate that gives the sensitive tint of a specimen between
crossed nicols. Pryor, 3
c. The mica plate that retards yellow light. Pryor, 3
d. In polarized-light microscopy, an optical device that may be inserted
into the light train to alter light interference after passage through, or
reflection by, a crystalline material; e.g., quartz wedge, mica plate,
gypsum plate, or Bertrand lens.
e. In polarized-light microscopy, an optical compensator that may be
inserted into the light train to alter birefringence after light passage
through or reflection by an anisotropic material; e.g., quartz wedge, mica
plate, gypsum plate, or Berek compensator. Syn:gips plate;
glimmer plate; compensator. CF:Berek compensator; gypsum plate.




access road

A route constructed to enable plant, supplies, and vehicles to reach a
mine, quarry, or opencast pit. In remote and isolated regions, the
provision of an access road may be very costly. Nelson




accidental inclusion

See:xenolith; xenocryst.




accordion roller conveyor

A roller conveyor with a flexible latticed frame that permits variation in
length.




accretion vein

A vein formed by the repeated filling of a channelway and its reopening by
the development of fractures in the zone undergoing mineralization.




accumulation

a. In coal mining, bodies of combustible gases that tend to collect in
higher parts of mine workings and at the edge of goaves and wastes. They
are found in cavities, at ripping lips, at other sheltered places
protected from the ventilating current, and at the higher sides of rise
faces. Mason
b. The concentration or gathering of oil or gas in some form of trap.
Commercial accumulation is a volume or quantity sufficient for profitable
exploitation. AGI




accumulative rock

See:cumulate




accumulator

a. A cylinder containing water or oil under pressure of a weighted piston
for hydraulic presses, hoists, winches, etc. It is between the pumps and
the presses, keeps a constant pressure on the system, and absorbs shocks.
b. A storage battery.
c. In oceanography, a spring of rubber or steel attached to a trawling
warp, to lessen any sudden strain due to the trawl catching. CTD




accumulator conveyor

Any conveyor designed to permit accumulation of packages or objects.
Usually roller, live roller conveyor, roller slat conveyor, or belt
conveyor.




accuracy

The degree of conformity with a standard, or the degree of perfection
attained in a measurement. Accuracy relates to the quality of a result,
and is distinguished from precision, which relates to the quality of the
operation by which the result is obtained. AGI




acetamide

A trigonal mineral, CH3 CONH2 . Syn:acetic acid amine;
ethanamide.




acetic acid amine

See:acetamide




acetylene

The most brilliant of illuminating gases, C2 H2 . It may be
produced synthetically from its elements, by incomplete combustion of coal
gas, and commercially from calcium carbide, CaC2 . It also may be
produced by reaction with water. Used in manufacturing explosives. Formerly used as an illuminating gas in mines and around drill rigs. When
combined with oxygen, acetylene burns to produce an intensely hot flame
and hence now is used principally in welding and metal-cutting flame
torches. Syn:ethyne; ethine. CF:gas
Standard, 2; Bennett; Long




acetylene lamp

See:carbide lamp




acetylene tetrabromide

Yellowish liquid; CHBr2 CHBr2 ; sp gr, 2.98 to 3.00; boiling
point, 239 to 242 degrees C with decomposition (at 760 mm); also, boiling
point, 151 degrees C (at 54 mm); melting point, 0.1 degrees C; and
refractive index, 1.638. Used for separating minerals by specific gravity;
a solvent for fats, oils, and waxes; a fluid in liquid gases; and a
solvent in microscopy. CCD, 2

achavalite

Former name for iron selenide, FeSe .




Acheson graphite

Artificial graphite made from coke by electric furnace heating.
Bennett




Acheson process

A process for the production of artificial or synthetic graphite. It
consists of sintering pulverized coke in the Acheson furnace at 2,760 to
3,316 degrees C. Henderson




achirite

Former name for dioptase.




achroite

A colorless variety of elbaite tourmaline used as a gemstone.




achromatic

In microscopy, a compound lens that does not spread white light into its
spectral colors. CF:aberration




acicular

a. A mineral consisting of fine needlelike crystals; e.g., natrolite.
Nelson
b. Slender needlelike crystal.
c. Refers to needlelike crystals. CF:equant; sagenitic; tabular;
rodlike.




acicular bismuth

See:aikinite




acicular powder

In powder metallurgy, needle-shaped particles. ASM, 1




aciculite

See:aikinite




acid

a. A solution of pH less than 7.0 at 25 degrees C.
b. A substance containing hydrogen that may be replaced by metals with the
formation of salts. CTD




acid Bessemer converter

One lined with acid refractories.




acid bottom and lining

The inner bottom and lining of a melting furnace, consisting of materials
like sand, siliceous rock, or silica brick, which give an acid reaction at
the operating temperature. Syn:acid lining




acid clay

a. A clay that is used mainly as a decolorant or refining agent, and
sometimes as a desulfurizer, coagulant, or catalyst.
b. A clay that yields hydrogen ions in a water suspension; a hydrogen
clay.




acid cure

In uranium extraction, sulfation of moist ore before leaching.
Pryor, 1




acid-dip survey

A method of determining the angular inclination of a borehole in which a
glass, test-tubelike bottle partly filled with a dilute solution of
hydrofluoric acid is inserted in a watertight metal case. When the
assemblage is lowered into a borehole and left for 20 to 30 min, the acid
etches the bottle at a level plane from which the inclination of the
borehole can be measured. CF:Kiruna method
acid test; acid-etch tube. Long




acid-dip test

See:acid-dip survey




acid drainage

Water with a pH of less than 6.0 and in which total acidity exceeds total
alkalinity; discharged from an active, inactive, or abandoned surface coal
mine and reclamation operation.




acid electric furnace

An arc furnace having an acid refractory hearth.




acid embrittlement

A form of hydrogen embrittlement that may be induced in some metals by
acid treatment. ASM, 1




acid-etch tube

A soda-lime glass tube charged with dilute hydrofluoric acid, left in a
borehole for 20 to 30 min to measure inclination as indicated by the angle
of etch line on the tube. May be fitted in a clinometer.
Syn:acid-etch vial; culture tube; etch tube; sargent tube.
See also:acid-dip survey


acid-etch vial

See:acid-etch tube




acid flux

Metallurgically acid material (usually some form of silica) used as a
flux. Bennett




acid-forming materials

Earth materials that contain sulfide minerals or other materials that, if
exposed to air, water, or weathering processes, form acids that may create
acid drainage.




acidic

a. A descriptive term applied to those igneous rocks that contain more
than 60% silica. Acidic is one of four subdivisions of a widely used
system for classifying igneous rocks based on their silica content:
acidic, intermediate, basic, and ultrabasic. AGI
b. Applied loosely to any igneous rock composed predominantly of
light-colored minerals having a relatively low specific gravity.
CF:felsic




acidization

The process of forcing acid into a limestone, dolomite, or sandstone in
order to increase permeability and porosity by dissolving and removing a
part of the rock constituents. It is also used to remove mud injected
during drilling. The general objective of acidization is to increase
productivity. Syn:acidizing




acidize

To treat a limestone or dolomitic formation with dilute hydrochloric acid
to enlarge its void spaces. Wheeler, R.R.




acidizing

See:acidization




acid leach

Metallurgical process for dissolution of metals by means of acid solution.
Examples include extraction of copper from oxide- or sulfide-bearing ore
and dissolution of uranium from sandstone ores. Acid leaching can occur on
heap-leach pads or in situ.




acid lining

See:acid bottom and lining




acid mine drainage

a. Acidic drainage from bituminous coal mines containing a high
concentration of acidic sulfates, esp. ferrous sulfate.
See also:acid water
b. Drainage with a pH of 2.0 to 4.5 from mines and mine wastes. It results
from the oxidation of sulfides exposed during mining, which produces
sulfuric acid and sulfate salts. The acid dissolves minerals in the rocks,
further degrading the quality of the drainage water. AGI




acid mine water

a. Mine water that contains free sulfuric acid, mainly due to the
weathering of iron pyrites. A pit water, which corrodes iron pipes and
pumps, usually contains a high proportion of solids per gallon,
principally the sulfates of iron, chiefly ferrous and alumina.
See also:acid water
b. Where sulfide minerals break down under chemical influence of oxygen
and water, the mine drainage becomes acidic and can corrode ironwork. If
it reaches a river system, biological damage may also result.
Pryor, 3




acid neutralizers

Calcium carbonate, CaCO3 , magnesium carbonate, MgCO3 , and
china clay, which neutralize free acids, thereby preventing explosives
from decomposing in storage. They also have a cooling effect and tend to
reduce the sensitivity of the explosive. Cooper




acid open-hearth steel

Low-phosphorus pig iron treated in an acid (silica or sand)-lined furnace.
Mersereau, 2




acid ore

See:siliceous ore




acid process

A steelmaking process--Bessemer, open-hearth, or electric--in which the
furnace is lined with a siliceous refractory, and for which pig iron low
in phosphorus is required, as this element is not removed.
See also:acid steel; basic process. CTD




acid-recovery operator

In the coke products industry, a person who recovers sulfuric acid used in
processing coke-gas byproducts by cooking sludge with steam in acid
regenerator pots. Syn:acid regenerator




acid refractory material

A general term for those types of refractory material that contain a high
proportion of silica; e.g., silica refractories (greater than 92% SiO (sub
2) ) and siliceous refractories (78% to 92% SiO2 ). The name
derives from the fact that silica behaves chemically as an acid and at
high temperatures reacts with bases such as lime or alkalies. Dodd




acid refractory product

Refractory product made of clay-silica mixture or pure silica.
Rosenthal




acid regenerator

See:acid-recovery operator




acid rock drainage

Drainage that occurs as a result of natural oxidation of sulfide minerals
contained in rock that is exposed to air and water. It is not confined to
mining activities, but can occur wherever sulfide-bearing rock is exposed
to air and water. Abbrev. ARD.




acid slag

Slag that contains substantial amounts of active silica.


acid sludge

Products of refining of tar, shale oil, and petroleum in which sulfuric
acid reacts to form a sulfonic acid mixture, green acids, and mahogany
acids and salts. Used in the flotation process and in proprietary
collector agents for flotation of iron ores. Pryor, 1




acid soil

A soil with a pH of less than 7.0. AGI




acid steel

Steel melted in a furnace with an acid bottom and lining and under a slag
containing an excess of an acid substance, such as silica.
See also:acid process




acid strength

Related to ability to liberate hydrogen ions to solution, and hence to
electrical conductivity of equivalent aqueous solutions of acids.
Pryor, 3




acid test

a. See:acid-dip survey
b. A severe or decisive trial, as of usability or authenticity.
Long




acid water

Water charged naturally with carbon dioxide. Also applied to natural
waters containing sulfur compounds, esp. sulfates.
See also:acid mine water; acid mine drainage.




aciform

Needle-shaped.




aciniform

A mineral aggregate shaped like a cluster of grapes. Also, full of small
kernels like a grape. Syn:acinose; acinous.




acinose

a. Grapelike; applied to the structure of clustered mineral aggregates.
Syn:aciniform; acinous.
b. Granulated; like grape seeds; applied to the texture of some mineral
aggregates.




acinote

Former name for actinolite.




acinous

See:aciniform; acinose.




aclinal

A little-used term said of strata that have no inclination; horizontal.
Syn:aclinic




aclinic

See:aclinal




aclinic line

The line through those points on the Earth's surface at which the magnetic
inclination is zero. The aclinic line is a particular case of an isoclinic
line. Hunt




acmite

A brown variety of aegirine having pointed terminations.
See also:aegirine; pyroxene.




acopolado

Mex. Ore containing 50 to 60 oz/st (1.56 to 1.88 kg/t) of silver.
Hess




acoustic

Used when the term that it modifies designates something that has the
properties, dimensions, or physical characteristics associated with sound
waves. Hy




acoustical well logging

Any determination of the physical properties or dimensions of a borehole
by acoustical means, including measurement of the depth of fluid level in
a well. AGI




acoustic attenuation log

In theory, a log designed to measure the manner in which the energy of
elastic waves is dissipated in passing through rock. Although no practical
log of this type has yet evolved, the belief that a log of this parameter
would permit the estimation of the permeability of formations would seem
to ensure such a development since no log has been developed to record
permeability. Wyllie




acoustic dispersion

The change of speed of sound with frequency. Hunt




acoustic impedance

The acoustic impedance of a given surface area of an acoustic medium
perpendicular, at every point, to the direction of propagation of
sinusoidal acoustic waves of given frequency, and having equal acoustic
pressures and equal volume velocities per unit area at every point of the
surface at any instance, is the quotient obtained by dividing (1) the
phasor corresponding to the acoustic pressure by (2) the phasor
corresponding to the volume velocity. See also:impedance


acoustic interferometer

An instrument for making physical observations upon standing waves. It may
be used, e.g., to measure velocity, wavelength, absorption, or impedance.
Hunt




acoustic log

A continuous record made in a borehole showing the velocity of sound waves
over short distances in adjacent rock; velocity is related to porosity and
nature of the liquid occupying pores. AGI




acoustic-radiation pressure

A unidirectional steady-state pressure exerted upon a surface exposed to
an acoustic wave. Such a steady pressure is usually quite small in
magnitude and is really observable only in the presence of very intense
sound waves. Hunt




acoustic radiometer

An instrument for measuring acoustic-radiation pressure by determining the
unidirectional steady-state force resulting from reflection or absorption
of a sound wave at its boundaries. Hunt




acoustic resistance

Product of longitudinal wave velocity and density, being the property that
controls the reflective power at a boundary plane. Schieferdecker




acoustics

The study of sound, including its production, transmission, reception, and
utilization, esp. in fluid media such as air or water. With reference to
Earth sciences, it is esp. relevant to oceanography. The term is sometimes
used to include compressional waves in solids; e.g., seismic waves.
AGI




acoustic scattering

The irregular reflection, refraction, or diffraction of sound waves in
many directions. Hy




acoustic sounding

The indirect evaluation of water depth, using the principle of measuring
the length of time necessary for a sound wave to travel to the bottom,
reflect, and travel back to the water surface. Hunt




acoustic-strain gage

An instrument for measuring strains; e.g., in concrete linings to shafts
or roadways. It contains a length of fine wire under tension, the tension
being varied by the strain to which the gage is subjected. The measurement
made is that of the frequency of vibration of the wire when it is plucked
by means of an electromagnetic impulse, and this measurement can be made
with great accuracy. The gage is highly stable, and readings can be made
over a period of years without any fear of zero drift.
See also:electrical resistance strain gage; mechanical extensometer.
Nelson




acoustic theodolite

An instrument designed to provide a continuous vertical profile of ocean
currents at a specific location. Hunt




acoustic wave

a. The waves that contain sound energy and by the motion of which sound
energy is transmitted in air, in water, or in the ground. The wave may be
described in terms of change of pressure, of particle displacement, or of
density. AGI
b. Used increasingly to study the physical properties of rocks and
composition of gases. Investigations may be made both in situ and in the
laboratory. Nelson




acquired lands

Defined by the U.S. Department of the Interior as "lands in Federal
ownership which were obtained by the Government through purchase,
condemnation, or gift, or by exchange for such purchased, condemned, or
donated lands, or for timber on such lands. They are one category of
public lands." Public land laws are generally inapplicable to acquired
lands. SME, 1




acre

a. A measure of surficial area, usually of land. The statute acre of the
United States and England contains 43,560 ft2 (4,840 yd2;
4,047 m2 ; or 160 square rods). The so-called Scotch acre
contains about 6,150 yd2 (5,142 m2 ), and the Irish acre
7,840 yd2 (6,555 m2 ). There are various special or
local acres in England (as in Cheshire or among the hop growers), varying
from 440 yd2 (368 m2 ) to more than 10,000 yd2
(8,361 m2 ). Standard, 2
b. Can. In Quebec, a linear measure that equals the square root of 43,560,
or approx. 208.7 ft (63.6 m). Fay
c. For the calculation of coal reserves, a convenient rule is to allow
1,200 st/ft (coal thickness) per acre (8,821 t/m/ha). For known and
dependable areas, 1,500 st/ft per acre (11,027 t/m/ha) may be used.
Nelson




acreage rent

Royalty or rent paid by the lessee for working and disposing of minerals
at the rate of so much per acre.




acre-foot

The quantity of water that would cover 1 acre, 1 ft deep (1 ha, 13.6 cm
deep). One acre-foot contains 43,560 ft3 (1,233 m3 ).




acre-inch

The volume of water, soil, or other material that will cover 1 acre, 1 in
deep (1 ha, 1.1 cm deep). AGI




acre-yield

The average quantity of oil, gas, or water recovered from 1 acre (0.4 ha)
of a reservoir. AGI




actetic acid amine

See:acetamide




actinide

A chemical element with atomic number greater than 88; all are
radioactive. Syn:actinide element




actinide element

a. One of the group of chemical elements of increasing atomic number,
starting with actinium (atomic number 89) and extending through atomic
number 103. These elements occupy one single place in the extended
periodic table, in the same group into which the rare-earth elements
(lanthanides) are classified. See also:actinide
b. One of the radioactive elements, atomic numbers 89 to 103.
Hurlbut




actinolite

A monoclinic mineral, 2[Ca2 (Mg,Fe)5 Si8 O22
(OH)2 ] in the hornblende series Mg/(Mg+Fe2+ ) = 0.5 to
0.89 of the amphibole group; forms a series with tremolite; green, bladed,
acicular, fibrous (byssolite asbestos), or massive (nephrite jade);
prismatic cleavage; in low-grade metamorphic rocks. Syn:actinote;
strahlite. CF:tremolite


actinote

See:actinolite




activated alumina

Highly porous, granular aluminum oxide that preferentially absorbs liquids
from gases and vapors, and moisture from some liquids.
McGraw-Hill, 1




activated carbon

Carbon, mostly of vegetable origin, and of high adsorptive capacity.
Syn:activated charcoal




activated charcoal

See:activated carbon




activated clay

A clay whose adsorbent character or bleaching action has been enhanced by
treatment with acid. CCD, 2




activated coal plow

With a view to applying the coal plow to seams too hard to be sheared by
the normal cutting blade, German mining engineers have developed various
types of power-operated cutters. One consists of a series of
compressed-air picks mounted above each other; another, of a resonance
pattern, houses two high-speed motors eccentrically mounted and rotating
in opposite directions. The latter imparts a vibration to the cutting edge
equivalent to 2,500 blows per minute with a stroke of 3/16 to 1/4 in (4.8
to 6.4 mm) and a force of approx. 200 st (181 t). Mason




activated plow

See:Huwood slicer




activating agent

a. A substance that when added to a mineral pulp promotes flotation in the
presence of a collecting agent. Syn:activator
b. Reagent used particularly in differential mineral flotation to help
cleanse the mineral surface so that a collector may adhere to it and
permit or aid its floatability. Frequently used to allow floating minerals
that had been previously depressed. Mitchell




activation

a. In the flotation process of mineral dressing, the process of altering
the surface of specific mineral particles in a mineral pulp to promote
adherence of certain reagents. Pryor, 3
b. The changing of the passive surface of a metal to a chemically active
state. CF:passivation
c. In the flotation process of ore beneficiation, the process of altering
the surface of specific mineral particles in an ore pulp to promote
adherence of certain reagents. Henderson
d. The process of making a material radioactive by bombardment with
neutrons, protons, or other nuclear particles.
See also:activation analysis




activation analysis

A method for identifying and measuring the chemical elements in a sample
to be analyzed. The sample is first made radioactive by bombardment with
neutrons, charged particles, or other nuclear radiation. The newly
radioactive atoms in the sample give off characteristic nuclear radiations
that can identify the atoms and indicate their quantity.
See also:activation




activator

a. In flotation, a chemical added to the pulp to increase the floatability
of a mineral in a froth or to refloat a depressed (sunk) mineral. Also
called activating reagent. CTD
b. A reagent that affects the surface of minerals in such a way that it is
easy for the collector atoms to become attached. It has the opposite
effect of a depressor. CF:depressor
c. A substance that is required in trace quantities to impart luminescence
to certain crystals. CCD, 2
d. Ions that are photon emitters. Van Vlack
e. Any agent that causes activation. See also:activating agent
Bennett




active agent

Surface-active substance that immunizes solids against a parting liquid.
Hess




active earth pressure

The minimum value of lateral earth pressure exerted by soil on a
structure, occurring when the soil is allowed to yield sufficiently to
cause its internal shearing resistance along a potential failure surface
to be completely mobilized. See also:surcharge
CF:passive earth pressure




active entry

An entry in which coal is being mined from a portion thereof or from
connected sections. USBM, 1




active fault

One liable to further movement. CF:passive fault




active layer

a. The surficial deposit that undergoes seasonal changes of volume,
swelling when frozen or wet, and shrinking when thawing and drying.
AGI
b. A surface layer of ground, above the permafrost, that is frozen in the
winter and thawed in the summer. Its thickness ranges from several
centimeters to a few meters. AGI




active mining area

a. The area, on and beneath land, used or disturbed in activity related to
the extraction, removal, or recovery of coal from its natural deposits.
This term excludes coal preparation plants, areas associated with coal
preparation plants, and post-mining areas. SME, 1
b. The area in which active mining takes place relative also to extraction
of metal ores, industrial minerals, and other minerals of economic value.




active workings

All places in a mine that are ventilated and inspected regularly.
Federal Mine Safety




activity

a. In nuclear physics, the rate of decay of atoms by radioactivity. It is
measured in curies. Bennett
b. The ideal or thermodynamic concentration of a substance, the
substitution of which for the true concentration, permits the application
of the law of mass action. See also:ionization constant




actual age

See:absolute age




actual breaking strength

The breaking load obtained from a tensile test to destruction on a sample
of rope. Hammond


actual horsepower

The horsepower really developed, as proved by trial. Standard, 2




actual performance curve

A performance curve showing the results actually obtained from a coal
preparation treatment. BS, 5




actuated roller switch

A switch placed in contact with the belt conveyor immediately preceding
the conveyor it is desired to control. In the centrifugal sequence control
switch, a driving pulley bears against the driving belt; as the latter
moves, the pulley rotates and the governor weights attached to the pulley
shaft are flung out and so complete an electrical pilot circuit and thus
start the subsidiary belt. Nelson




acute bisectrix

a. The line that bisects the acute angle of the optic axes of biaxial
minerals. Fay
b. The angle <90 degrees between the optic axes in a biaxial crystal, bxa.
CF:optic angle




adamantine

a. Like the diamond in luster. Webster 3rd
b. Diamond hard. A commercial name for chilled steel shot used in the
adamantine drill, which is a core-barrel type of rock-cutting drill with a
cutting edge fed by these shots. CF:vitreous




adamantine luster

Diamondlike luster. Hurlbut




adamellite

See:quartz monzonite




adamic earth

A term used for common clay, in reference to the material of which Adam,
the first man, was made; specif. a kind of red clay. AGI




adamite

A rare hydrous zinc arsenate, Zn2 (AsO4 )(OH) , occurring
granular or in crusts and crystallizing in the orthorhombic system. Weakly
radioactive; variable color--yellowish, greenish, or violet, rarely
colorless or white; found in the oxidized zone of zinc orebodies.
Associated with smithsonite, calcite, malachite, hemimorphite, limonite,
and azurite. Small amounts of uranium have been found in some specimens of
adamite. Fay; Crosby




adamsite

A greenish-black muscovite found in a schist at Derby, VT; has been called
margarodite. Dana, 1
[?(?Æk DICTIONARY TERMS:Adam's snuffbox Hollow, roughly rectangular pebble
[\B]Adam's snuffbox[\N]




ada mud

A conditioning material that may be added to drilling mud in order to
obtain satisfactory cores and samples of formations. Williams




adapter trough

A short section of a shaker conveyor trough that serves as a connecting
link between any two sizes of trough. Jones, 1




added diamonds

As used by the diamond-bit manufacturing industry, the number or carat
weight of new diamonds that must be added to the resettable diamonds
salvaged from a worn bit in order to have enough to set a new bit.
Long




additive

A correction applied to times of seismic reflections measured from an
arbitrary time origin. The additive is normally applied for the purpose of
translating the time origin to correspond to the datum elevation chosen
for computation, and it is algebraic in sign. AGI




addlings

A term used in the northern and parts of other coalfields in Great Britain
to describe earnings or wages. Nelson




Adeline steelmaking process

A process of producing precision castings of steel or steel alloys, which
comprises first forming the steel or steel alloy in molten form by the
aluminothermic process, by igniting a mixture of iron ore and aluminum;
then running the molten metal into a mold prepared by packing a refractory
mold composition around a model made of wax or other comparatively
low-melting-point substance and heating to melt out the wax and
consolidate the mold; and finally centrifuging the mold. Osborne




adelite

a. An orthorhombic mineral, CaMg(AsO4 )(OH) ; occurs with manganese
ores.
b. The mineral group adelite, austinite, conichalcite, duftite, and
gabrielsonite.




ader wax

See:ozocerite




adhesion

a. The molecular force holding together two different substances that are
in contact, as water in the pore spaces of a rock. CF:cohesion
b. Shearing resistance between soil and another material under zero
externally applied pressure. ASCE
c. In the flotation process, the attachment of a particle to air-water
interface or to a bubble.




adhesive slate

A very absorbent slate that adheres to the tongue if touched by it.
Standard, 2




adiabatic calorimeter

A calorimeter that practically remains unaffected by its surroundings and
neither gains nor loses heat. Osborne


adiabatic compression

Compression in which no heat is added to or subtracted from the air and
the internal energy of the air is increased by an amount equivalent to the
external work done on the air. The increase in temperature of the air
during adiabatic compression tends to increase the pressure on account of
the decrease in volume alone; therefore, the pressure during adiabatic
compression rises faster than the volume diminishes. Lewis




adiabatic efficiency

A compression term obtained by dividing the power theoretically necessary
to compress the gas and deliver it without loss of heat, by the power
supplied to the fan or compressor driveshaft.




adiabatic expansion

Expansion in which no heat is added to or subtracted from the air, which
cools during the expansion because of the work done by the air.
Lewis




adiabatic temperature

The temperature that would be attained if no heat were gained from or lost
to the surroundings. Newton, 1




adiabatic temperature change

The compression of a fluid without gain or loss to the surroundings when
work is performed on the system and produces a rise of temperature. In
very deep water such a rise of temperature occurs and must be considered
in the vertical temperature distribution. Hy




adinole

An argillaceous sediment that has undergone albitization as a result of
contact metamorphism along the margins of a sodium-rich mafic intrusion.
CF:spilosite; spotted slate. AGI




adipite

An aluminosilicate of calcium, magnesium, and potassium having the
composition of chabazite. Dana, 1




adipocerite

See:hatchettite




adipocire

See:hatchettite




a direction

See:a axis




adit

a. A horizontal or nearly horizontal passage driven from the surface for
the working or dewatering of a mine. If driven through the hill or
mountain to the surface on the opposite side, it would be a tunnel.
Syn:drift; adit level. See also:tunnel
b. As used in the Colorado statutes, it may apply to a cut either open or
undercover, or open in part and undercover in part, dependent on the
nature of the ground.
c. A passage driven into a mine from the side of a hill.
Statistical Research Bureau




adit end

The furthermost end or part of an adit from its beginning or the very
place where the miners are working underground toward the mine.
Hess




adit level

Mine workings on a level with an adit. See also:adit




adjacent sea

A sea adjacent to and connected with the oceans, but semienclosed by land.
The North Polar, Mediterranean, and Caribbean Seas are examples.
Syn:marginal sea




adjustment of error

Method of distributing the revealed irregularities over a series of
results. Pryor, 3




adjutage

Nozzle or tube from which hydraulic water is discharged. Syn:ajutage




admission

See:admittance




admittance

a. In a crystal structure, substitution of a trace element for a major
element of higher valence; e.g., Li+ for Mg2+ . Admitted
trace elements generally have a lower concentration relative to the major
element in the mineral than in the fluid from which the mineral
crystallized. CF:capture; camouflage. Syn:admission
b. The reciprocal of impedance or the ratio of complex current to voltage
in a linear circuit. AGI




adobe

A fine-grained, usually calcareous, hard-baked clayey deposit mixed with
silt, usually forming as sheets in the central or lower parts of desert
basins, as in the playas of the southwestern United States and in the arid
parts of Mexico and South America. It is probably a windblown deposit,
although it is often reworked and redeposited by running water.
AGI




adobe charge

A mud-covered or unconfined explosive charge fired in contact with a rock
surface without the use of a borehole. Syn:bulldoze; mudcapping.
Atlas




adobe flat

A generally narrow plain formed by sheetflood deposition of fine sandy
clay or adobe brought down by an ephemeral stream, and having a smooth,
hard surface (when dry) usually unmarked by stream channels. AGI


adobe shot

Ordinarily referred to as a dobe shot. A stick or part of a stick of
dynamite is laid on the rock to be broken and covered with mud to add to
the force of the explosion. A mudcap shot. Hess




adsorption

a. Adherence of gas molecules, or of ions or molecules in solution, to the
surface of solids with which they are in contact, as methane to coal or
moisture to silica gel. CF:absorption
b. The assimilation of gas, vapor, or dissolved matter by the surface of a
solid or liquid.
c. The attachment of a thin film of liquid or gas, commonly monomolecular
in thickness, to a solid substrate.




adsorption analysis

Separation by differential adsorption. Pryor, 1




adular

See:adularia




adularescence

a. A milky white to bluish sheen in gemstones. CMD
b. The changeable white to pale bluish luster of an adularia cut cabochon.
Webster 3rd
c. A floating, billowy, white or bluish light, seen in certain directions
as a gemstone (usually adularia) is turned, caused by diffused reflection
of light from parallel intergrowths of another feldspar of slightly
different refractive index from the main mass. Syn:schiller




adularia

A colorless, moderate- to low-temperature variety of orthoclase feldspar
typically with a relatively high barium content. Syn:adular




adularia moonstone

Precious moonstone, a gem variety of adularia.




advance

a. The work of excavating as mining goes forward in an entry and in
driving rooms; to extract all or part of an area; first mining as
distinguished from retreat. BCI
b. Rate at which a drill bit penetrates a rock formation. Long
c. Feet drilled in any specific unit of time. Long
d. The linear distance (in feet or meters) driven during a certain time in
tunneling, drifting, or in raising or sinking a shaft. Fraenkel




advance development

S. Afr. Development to provide an ore reserve in advance of mining
operations. Beerman




advanced gallery

In tunnel excavation, a small heading driven in advance of the main
tunnel.




advanced materials

Materials developed since 1960 and being developed at present that exhibit
greater strength, higher strength-density ratios, greater hardness, and/or
one or more superior thermal, electrical, optical, or chemical properties,
when compared with traditional materials (Sorrel, 1987) and with
properties needed to perform a specific function and often entirely new
functions. SME, 1




advance gate

Gate road that is driven simultaneously with the longwall coal face, when
the advancing longwall technique is used, but which is maintained some 10
to 20 yd (9 to 18 m) or more in advance of the face. The area immediately
ahead of the coal face is therefore preexplored, and steps can be taken to
cope with minor disturbances and thus prevent a serious loss of output.
Nelson




advance overburden

Overburden in excess of the average overburden-to-ore ratio that must be
removed in opencut mining. Mining




advance per round

The length, measured along the longitudinal axis of the working, tunnel,
or gallery, of the hollow space broken out by each round of shots. For
raises, it is upward advance; for sunk shafts, downward advance.
Fraenkel




advance stope

A stope in which sections of the face or some pillars are a little in
advance of the others. This is achieved either by beginning the stoping of
the section that is to be advanced earlier, or by proceeding more quickly.
Stoces




advance stripping

The removal of overburden required to expose and permit the minable grade
of ore to be mined. The removal of overburden is known as stripping.




advance wave

The air-pressure wave preceding the flame in a coal-dust explosion. The
bringing of the dust into suspension is accomplished by such a wave and
the violent eddies resulting therefrom. Syn:pioneer wave
Rice, 2




advance working

Mine working that is being advanced into the solid, and from which no
pillar is being removed. See also:first working




advancing

Mining from the shaft out toward the boundary. See also:working out
Stoces




advancing longwall

A longwall mining technique, most commonly found in European coal mines,
where the gate roads are advanced while the longwall face is advanced
toward the mining limits. The gate roads are maintained throughout the
worked-out portion of the longwall panel.




adventurine

Spelling variant of aventurine.


adverse

To oppose the granting of a patent to a mining claim.




adverse claim

A claim made to prevent the patenting of part of the ground within the
area in question; e.g., an adverse claim is made by a senior locator to
exclude the part of his or her claim that is overlapped by the claim of a
junior locator, when the junior locator is applying for patent.
Lewis




adverse intent

The terms "claim of right," "claim of title," and "claim of ownership,"
when used in the books to express adverse intent, mean nothing more than
the intention of the dissessor to appropriate and use the land as his or
her own to the exclusion of all others, irrespective of any semblance or
shadow of actual title. Ricketts




advertised out

A term used to express the result of the action of a joint owner of a
mining claim who by proper notices causes the interest of the co-owner to
be forfeited for failure to perform his or her share of the assessment
work.




aedelforsite

A name given to (1) a mixture of wollastonite, quartz, and feldspar from
Edelfors, Sweden; (2) impure wollastonite from Giellebak, Sweden (called
also gillebackit); and (3) impure laumontite, under the impression that
they were new minerals. Syn:edelforsite




aedelite

See:prehnite




AED process

An electrostatic process under development, in which fine-size dry coal is
passed through an ionized field that selectively charges the coal and the
liberated mineral matter. The output of the ionizer is then fed into an
electrostatic separator where the coal and impurities are separated.




aegirine

A sodium-ferric iron silicate, NaFe3+ Si2 O6 ,
occurring commonly in soda-rich igneous rocks; monoclinic; Mohs hardness,
6 to 6.5; sp gr, 3.40 to 3.55. Syn:acmite; aegirite.
See also:pyroxene




aegirine-augite

A monoclinic mineral, (Ca,Na)(Ca,Mg,Fe)Si2 O6 , in the range
20% augite to 20% aegirine end members of the pyroxene group. Formerly
called acmite-augite, aegirineaugite.




aegirite

Former spelling of aegirine. See also:pyroxene; aegirine.




aenigmatite

a. A triclinic mineral, Na2 Fe52+ TiSi6 O
20 ; a rare titanium-bearing silicate; black color; found associated
with alkalic rocks. Dana, 4
b. The mineral group aenigmatite, rhoenite, serendibite, and welshite.
CF:enigmatite




aeolian

See:eolian




Aeonite

Trade name for a bitumen allied to wurtzilite. Similar to elaterite.
Tomkeieff; English




aerate

a. To expose to the action of the air; to supply or to charge with air.
Standard, 2
b. To charge with carbon dioxide or other gas, as soda water.
Standard, 2




aeration

a. The introduction of air into the pulp in a flotation cell in order to
form air bubbles. BS, 5
b. In mineral beneficiation, use of copious air bubbled into mineral pulps
(1) to provide oxygen in cyanidation, (2) to prevent settlement of solids,
and (3) to remove aerophilic minerals in froth flotation by binding them
into a mineralized froth that is temporarily stabilized by frothing
agents. Pryor, 1
c. The process of relieving the effects of cavitation by admitting air to
the section affected. Seelye, 1




aeration zone

The zone in which the interstices of the functional permeable rocks are
not (except temporarily) filled with water under hydrostatic pressure; the
interstices are either not filled with water or are filled with water that
is held by capillarity. Rice, 1




aerator

An apparatus for charging water with gas under pressure, esp. with carbon
dioxide. Standard, 2




aerial

Relating to the air or atmosphere. Subaerial is applied to phenomena
occurring under the atmosphere as subaqueous is applied to phenomena
occurring underwater. Fay




aerial cableway

An arrangement of overhead cable supporting a traveling carriage from
which is suspended a skip or container that can be lowered and raised at
any desired point. Nelson




aerial mapping

The taking of aerial photographs for making maps and for geologic
interpretation. AGI




aerial photograph

Any photograph taken from the air, such as a photograph of a part of the
Earth's surface taken by a camera mounted in an aircraft.
Syn:air photograph


aerial photomosaic

See:mosaic




aerial railroad

A system of cables from which to suspend cars or baskets, as in hoisting
ore. See also:aerial tramway




aerial ropeway

System of ore transport used in rough or mountainous country. A cable is
carried on pylons, and loaded buckets are (1) towed from loading point to
discharge, (2) suspended from a carriage running on this cable and then
returned empty along a second cable, or (3) the whole cable moves
continuously carrying buckets that hang from saddle clips and are loaded
and discharged automatically or by hand control. Syn:overhead ropeway
See also:bicable; monocable; aerial tramway; telpher. Pryor, 3




aerial spud

A cable for moving and anchoring a dredge. Fay




aerial survey

a. A survey using aerial photographs as part of the surveying operation.
AGI
b. The taking of aerial photographs for surveying purposes. AGI




aerial tramway

A system for the transportation of material, such as ore or rock, in
buckets suspended from pulleys or grooved wheels that run on a cable,
usually stationary. See also:tramway; aerial railroad; aerial ropeway.
Fay; Peele




aerobe

An organism that lives in the presence of free oxygen. The oxygen is
usually used in the cell's metabolism. See also:aerobic




aerobic

a. Said of an organism (esp. a bacterium) that can live only in the
presence of free oxygen; also, said of its activities. Syn:aerobe
AGI
b. Said of conditions that can exist only in the presence of free oxygen.
CF:anaerobic




aeroclay

Clay, particularly china clay, that has been dried and air separated to
remove any coarse particles. Dodd




aerodynamical efficiency

This furnishes a measure of the capacity of a fan to produce useful
depression (or positive pressure in the case of a forcing fan) and
indicates the extent to which the total pressure produced by the fan is
absorbed within the fan itself. Sinclair, 1




aerodynamic diameter

The diameter of a unit density sphere having the same terminal settling
velocity as the particle in question. ANSI




aerodynamic fan

A fan that consists of several streamlined blades mounted in a revolving
casing. The cross section and spacing of the blades are designed
aerodynamically. This design ensures that the air flows without
recirculation between the blades and leaves the rotor in a steady and
regularly distributed stream. This appreciably reduces frictional,
conversion, and recirculation losses. Fans of a convenient size can handle
large volumes of air at the highest pressures likely to be required in
mine ventilation.




aerodynamic instability

Flutter that may occur in a structure exposed to wind force. This form of
instability can be guarded against by suitable design. Hammond




aeroembolism

a. The formation or liberation of gases in the blood vessels of the body,
as brought on by a change from a high, or relatively high, atmospheric
pressure to a lower one. Hunt
b. The disease or condition caused by the formation or liberation of gases
in the body. The disease is characterized principally by neuralgic pains,
cramps, and swelling, and sometimes results in death.
Syn:decompression sickness




aerofall mill

A short, cylindrical grinding mill with a large diameter, used dry, with
coarse lumps of ore, pebbles, or steel balls as crushing bodies. The mill
load is flushed with an air stream to remove finish mesh material.
Pryor, 3




aerofloc

Synthetic water-soluble polymer used as a flocculating agent.
Bennett




aerofoil-vane fan

An improved centrifugal-type mine fan. The vanes, of aerofoil section, are
curved backward from the direction of rotation. This fan is popular in
British coal mines, and total efficiencies of about 90% have been
obtained. See also:mine-ventilation fan




aerohydrous

a. Enclosing a liquid in the pores or cavities, as some minerals.
Standard, 2
b. Characterized by the presence of both air and water.
Standard, 2




aeroides

Pale sky-blue aquamarine beryl.




aeromagnetic prospecting

A technique of geophysical exploration of an area using an airborne
magnetometer to survey that area. Syn:airborne magnetic prospecting
AGI




aerometer

An instrument for ascertaining the weight or the density of air or other
gases. Webster 3rd


aerosite

Former name for pyrargyrite.




aerosol

a. A suspension of ultramicroscopic solid or liquid particles in air or
gas, as smoke, fog, or mist. Webster 3rd
b. Particles, solid or liquid, suspended in air. ANSI
c. A sol in which the dispersion medium is a gas (usually air) and the
dispersed or colloidal phase consists of solid particles or liquid
droplets, e.g., mist, haze, most smoke, and some fog. AGI




Aerosol

Trade name of strong wetting agent based on sulfonated bi-carboxy-acid
esters. Pryor, 3




aerugite

A grass-green to brown nickel arsenate, perhaps Ni17 As6 O
32 ; an analysis gave 48.77% nickel. It is an oxidized vein mineral.
Hess




aerugo

a. Copper carbonate, due to weathering of the metal; esp., the patina
adhering to old bronzes. Hess
b. Copper rust; verdigris; esp., green copper rust adhering to old
bronzes. Standard, 2




aeschynite

An orthorhombic mineral, (Ce,Ca,Fe,Th)(Ti,Nb)2 (O,OH)6 ;
radioactive; occurs in black sands and pegmatites.




aethiops mineral

A former name for metacinnabar; isometric HgS .




aetite

a. A nodule consisting of a hard shell of hydrated iron oxide within which
yellow iron oxide becomes progressively softer toward the center, which
may be hollow. Fay
b. See:eaglestone




affinity

In ion exchange, relative strength of attachment of competing ions for
anchorage on a resin. Pryor, 3




A-frame

a. Two poles or legs supported in an upright position by braces or guys
and used as a drill mast. Long
b. An open structure tapering from a wide base to a narrow load-bearing
top. Nichols, 2




A-frame headgear

A steel headgear consisting of two heavy plate A-frames, set astride the
shaft mouth. They are braced together and carry the heavy girders that
support the winding sheaves platform. It is a completely self-supporting
and rigid structure that leaves usable space around the shaft collar and
includes a guide-tower structure built over the shaft collar. A number of
these headgears have been erected in the Republic of South Africa.
Nelson




African emerald

a. A deceiving name for green fluor; also for green tourmaline.
b. An emerald from the Transvaal. It is usually quite yellowish green;
often dark and dull. Hardness, 7.5; sp gr, 2.72 to 2.79; refractive index,
1.58 to 1.59; birefringence, 0.007. Syn:Transvaal emerald
c. A term variously used for southern African emeralds (beryl), green
tourmaline, and other green gemstones from this region.




afterblast

During an explosion of methane and oxygen, carbon dioxide and steam are
formed. When the steam condenses to water a partial vacuum is created,
which causes an inrush or what is known as an afterblast. Cooper




afterblow

Continued blowing of air through Bessemer converter after flame has
dropped, for removal of phosphorus in steel production. Pryor, 3




afterbreak

In mine subsidence, a movement from the sides, the material sliding
inward, and following the main break, assumed to be at right angles to the
plane of the seam. The amount of this movement depends on several factors,
such as the dip, depth of seam, and nature of overlying materials.
Lewis




afterburst

a. A tremor as the ground adjusts itself to the new stress distribution
caused by new underground openings.
b. In underground mining, a sudden collapse of rock subsequent to a rock
burst.




aftercooler

A device for cooling compressed air between the compressor and the mine
shaft. By cooling and dehumidifying the air, and thus reducing its volume,
the capacity and efficiency of the pipeline are increased.
See also:air-conditioning process; intercooler. Nelson




afterdamp

The mixture of gases that remain in a mine after a mine fire or an
explosion of combustible gases. It consists of carbonic acid gas, water
vapor (quickly condensed), nitrogen, oxygen, carbon monoxide, and in some
cases free hydrogen, but usually consists principally of carbonic acid gas
and nitrogen, and is therefore irrespirable. See also:blackdamp; damp.
Fay




aftergases

Gases produced by mine explosions or mine fires. Fay




aftershock

An earthquake that follows a larger earthquake or main shock and
originates at or near the focus of the larger earthquake. Generally, major
earthquakes are followed by many aftershocks, which decrease in frequency
and magnitude with time. Such a series of aftershocks may last many days
for small earthquakes or many months for large ones. CF:foreshock
AGI




aftersliding

In mine subsidence, an inward movement from the side, resulting in a pull
or draw beyond the edges of the workings. Briggs


afwillite

A monoclinic mineral, Ca3 Si2 O4 (OH)6 ; it is
formed as portland cement is hydrated under special conditions, and where
calcium silicate is autoclaved (as in sand-lime brick manufacture).




agalite

A fine fibrous variety of talc pseudomorphous after enstatite.
Syn:asbestine




agalmatolite

A soft, waxy stone--such as pinite, pyrophyllite, or steatite--of a gray,
green, yellow, or brown shade; used by the Chinese to simulate jade for
carving small images, miniature pagodas, and similar objects.
Syn:figure stone; pagodite; lardite; lard stone.




agardite

A hexagonal mineral, (RE,Ca)Cu6 (AsO4 )3 (OH)6
.3H2 O ; mixite group. Lanthanum, yttrium, or cerium may
predominate among the rare earths.




agaric mineral

a. A soft, pulverulent hydrated silicate of magnesium in Tuscany, IT, from
which floating bricks can be made. Fay
b. A light, chalky deposit of calcium carbonate formed in caverns or
fissures in limestone. Syn:rock milk




agate

a. A kind of silica consisting mainly of chalcedony in variegated bands or
other patterns; commonly occupying vugs in volcanic and other rocks.
AGI
b. A translucent cryptocrystalline variety of variegated chalcedony
commonly mixed or alternating with opal and characterized by colors
arranged in alternating stripes or bands, in irregular clouds, or in
mosslike forms; occurs in virtually all colors, generally of low
intensity, in vugs in volcanic rocks and cavities in some other rocks.
CF:onyx
moss agate.




agate jasper

An impure variety of agate consisting of jasper with veins of chalcedony.
Syn:jaspagate




agate opal

Opalized agate. Fay




agatized wood

A variety of silicified wood which resembles any variety of agate.
See:silicified wood




age

a. The formal geochronologic unit of lowest rank, below epoch, during
which the rocks of the corresponding stage were formed. AGI
b. A term used informally to designate a length of geologic time during
which the rocks of any stratigraphic unit were formed. AGI
c. A division of time of unspecified duration in the history of the Earth,
characterized by a dominant or important type of life form; e.g., the age
of mammals. AGI
d. The time during which a particular geologic event or series of events
occurred or was marked by special physical conditions; e.g., the Ice Age.
AGI
e. The position of anything in the geologic time scale; e.g., the rocks of
Miocene age. It is often expressed in years. See also:geologic age
AGI




Agecroft device

A device placed in the rail track to arrest a forward runaway tram. The
front axle of a descending tram traveling at normal speed depresses the
catch and allows it to drop back in time for the back axle to pass over.
Should the tram be traveling at excessive speed, the tail end of the catch
arrests the rear axle. Mason




agent

a. The manager of a mining property. Zern
b. On a civil engineering contract, the responsible representative of the
contractor, acting for him or her in all matters. Hammond
c. Before nationalization in Great Britain, the term referred to the chief
official of a large coal mine or group of mines under the same ownership.
After nationalization, the equivalent term is group manager.
Nelson
d. A chemical added to pulp to produce desired changes in climate of the
system. Pryor, 3




age ratio

The ratio of daughter to parent isotope upon which the age equation is
based. For a valid age determination, (1) the isotope system must have
remained closed since solidification, metamorphism, or sedimentation, (2)
the decay constant must be known, and (3) the sample must be truly
representative of the rock from which it is taken. AGI




agglomerate belt flotation

A coarse-fraction concentration method used in milling pebble phosphate in
which conditioned feed at 70% to 75% solids is placed on a flat conveyor
belt traveling at a rate of about 75 ft/min (22.9 m/min). Water sprayed on
the surface of the pulp aerates the pulp, causing agglomerates of
phosphate particles to float to the side of the belt for removal. The
silica fraction travels the length of the belt and is permitted to flow
off the opposite end. Baffles are positioned at appropriate points along
the belt to stir the material so that trapped phosphate particles are
given an opportunity to float. Concentrate from the first belts or rougher
operation is cleaned on a second belt for further silica removal. Tailings
from the cleaner belt are recycled to the rougher circuit. Arbiter




agglomerate screening

A coarse-fraction concentration method used in milling pebble phosphate
that is based on flowing reagentized feed over a submerged sloping,
stationary screen. Agglomerated phosphate particles float on top of the
screen and are recovered at the lower end. Sand particles pass through the
screen and are removed as a tailings fraction. Each screen section is
approx. 3 ft (0.9 m) wide by 4 ft (1.2 m) long and treats 2 to 3 st/h (1.8
to 2.7 t/h) of feed. Arbiter




agglomerating value

A measure of the binding qualities of coal but restricted to describe the
results of coke-button tests in which no inert material is heated with the
coal sample. CF:agglutinating value




agglomeration

a. In beneficiation, a concentration process based on the adhesion of pulp
particles to water. Loosely bonded associations of particles and bubbles
are formed that are heavier than water; flowing-film gravity concentration
is used to separate the agglomerates from nonagglomerated particles.
Agglomeration also refers to briquetting, nodulizing, sintering, etc.
Gaudin, 1
b. See:kerosine flotation




agglutinate

A welded pyroclastic deposit characterized by vitric material binding the
pyroclasts, or sintered vitric pyroclasts. Also spelled agglutinite.
AGI




agglutinating power

See:caking index




agglutinating value

A measure of the binding qualities of a coal and an indication of its
caking or coking characteristics. Applicable with reference to the ability
of fused coal to combine with an inert material such as sand.
CF:agglomerating value




agglutinating-value test

A laboratory test of the coking properties of coal, in which a
determination is made of the strength of buttons made by coking a mixture
of powdered coal and 15 to 30 times its weight of sand.


agglutination

See:cementation




aggradation

a. The building up of the Earth's surface by deposition; specif., the
upbuilding performed by a stream in order to establish or maintain
uniformity of grade or slope. See also:gradation
Syn:upgrading
b. A syn. of accretion, as in the development of a beach. The spread or
growth of permafrost, under present climatic conditions, due to natural or
artificial causes. AGI




aggregate

a. A mass or body of rock particles, mineral grains, or a mixture of both.
AGI
b. Any of several hard, inert materials, such as sand, gravel, slag, or
crushed stone, mixed with a cement or bituminous material to form
concrete, mortar, or plaster, or used alone, as in railroad ballast or
graded fill. The term can include rock material used as chemical or
metallurgical fluxstone. See also:chippings; coarse aggregate;
fine aggregate; lightweight aggregate. AGI




aging

A change in the properties of a substance with time. See also:overaging;
precipitation hardening. Nelson




Agitair flotation machine

Uses air to separate aerophilic and hydrophilic particles. Low-pressure
air bubbles lift aerophilic particles to an overflow, leaving hydrophilic
particles behind. Pryor, 3




agitation dredging

Consists of pumping the discharge directly into the sea and using the tide
to carry the fines to deeper water areas. Agitation dredging is employed
only during ebb tide in tidal estuaries having swift tidal flows that will
disperse the accumulations of silt. Carson, 2




agitation ratio

In older type gravity concentrators, such as tables and vanners, the ratio
between the average diameter of a mineral particle and the diameter of a
gangue particle that travels at equal speed.




agitator

a. A tank in which very finely crushed ore is agitated with leaching
solution. Usually accomplished by means of a current of compressed air
passing up a central pipe and causing circulation of the contents of the
tank. Sometimes called a mixer. CTD
b. A device used to stir or mix grout or drill mud. Not to be confused
with shaker or shale shaker. Long
c. A device used to bring about a continuous vigorous disturbance in a
pulp; frequently used to assist bubble formation. BS, 5
d. Pac. See:settler




aglaite

A pseudomorph of spodumene in which the spodumene has been replaced by
muscovite either as pinite or as visible plates. Also called pihlite and
cymatolite in the belief that the material was a new mineral. Hess




agmatite

Migmatite with appearance of breccia. CF:contact breccia




agnesite

An early name for bismutite, Cornwall, U.K. Fay




agonic line

An isogonic line that connects points of zero magnetic declination. Its
position changes according to the secular variation of the Earth's
magnetic field. See also:isogonic line




agreement

The formal document by which the contractor and the authority mutually
agree to comply with the requirements of the drawings, specification,
schedule, conditions of tendering, and general conditions of contract and
the tender. See also:tender; contract. Nelson




agricolite

A former name for eulytite.




agricultural geology

The application of geology to agricultural needs, e.g., mineral deposits
used as fertilizers or the location of ground water. Syn:agrogeology
AGI




agricultural lime

a. Either ground quicklime or hydrated lime whose calcium and magnesium
content is capable of neutralizing soil acidity. ASTM
b. Lime slaked with a minimum amount of water to form calcium hydroxide.
CCD, 2




agrite

A brown, mottled calcareous stone. Schaller




agrogeology

See:agricultural geology




aguilarite

An orthorhombic mineral, Ag4 SeS .




ahlfeldite

A monoclinic mineral, NiSeO3 .2H2 O; forms a series with
cobaltomenite; rose colored; vitreous luster; no cleavage; conchoidal
fracture; strongly pleochroic, X rose, Y pale green, Z brown green; from
Pacajake, Bolivia. Am. Mineral., 1




A-horizon

In a soil profile, the uppermost zone from which soluble salts and
colloids have been leached and in which organic matter has accumulated.
See also:B-horizon

aikinite

a. An orthorhombic mineral, PbCuBiS3 ; sp gr, 6.1 to 6.8; an ore of
lead, copper, and bismuth. Syn:acicular bismuth; aciculite; needle ore;
acicular bismuth; aciculite.
b. Wolframite pseudomorphous after scheelite.




aimafibrite

See:hemafibrite




AIME

American Institute of Mining and Metallurgical Engineers.
Statistical Research Bureau




air

a. The mixture of gases that surrounds the Earth and forms its atmosphere;
composed by volume of 21% oxygen and 78% nitrogen; by weight about 23%
oxygen and 77% nitrogen. It also contains about 0.03% carbon dioxide, some
aqueous vapor, argon, and other gases. Hartman, 1
b. The current of atmospheric air circulating through and ventilating the
workings of a mine.
c. Atmospheric air delivered under compression to bottom of drill hole
through the drill stem and used in place of water to clear the drill bit
of cuttings and to blow them out of the borehole. Long
d. Air piped under compression to work areas and used to operate drilling
or mining machinery. See also:air circulation




airafibrite

See:hemafibrite




air-avid surface

A surface that seems to prefer contact with air to contact with water. A
particle (or mineral) of this sort will adhere to an air bubble and float
out of a flotation pulp; otherwise, the particle will not float. Also
called water-repellent surface; hydrophobic. CF:water-avid surface
Newton, 1




air barrage

The division of an opening in a mine by an airtight wall into two sides;
one side is used as an air intake, the other side as a return.




air bell

In froth flotation, the small air pocket inducted or forced into the pulp
at depth; e.g., bell and the two-walled semistable bubble after emergence
from pulp into froth have different characteristics and gas-to-liquid,
area-to-volume relationships, hence the distinction. These bubbles vary in
attractive and retaining power for aerophilic grains and are a critical
component of the flotation process. Syn:air bubble




air belt

In a cupola furnace, an annular air space around the furnace, from which
air is forced into the furnace. Henderson




airblast

a. A term improperly used by some diamond drillers as a syn. for air
circulation. See also:air circulation
b. A disturbance in underground workings accompanied by a strong rush of
air. The rush of air, at times explosive in force, is caused by the
ejection of air from large underground openings, the sudden fall of large
masses of rock, the collapse of pillars, slippage along a fault, or a
strong current of air pushed outward from the source of an explosion.
Long




airblasting

A method of blasting in which compressed air at very high pressure is
piped to a steel shell in a shot hole and discharged. BS, 12




air block

Air trapped in the upper end of an unvented inner tube of a double-tube
core barrel, which, when sufficiently compressed, acts like a solid and
stops further advance of core into the inner tube. Syn:air cushion
Long




airborne electromagnetic prospecting

Electromagnetic surveys carried out with airborne instruments.
Dobrin




airborne magnetic prospecting

See:aeromagnetic prospecting




airborne magnetometer

An instrument used to measure variations in the Earth's magnetic field
while being transported by an aircraft. See also:magnetometer
AGI




air box

a. A rectangular wooden pipe or tube made in lengths of 9 to 15 ft (2.7 to
4.6 m) for ventilating a heading or a sinking shaft. Fay
b. A box for holding air. Fay
c. The conduit through which air for heating rooms is supplied to a
furnace. Standard, 2




air breakers

A method of breaking down coal by the use of high-pressure compressed air.
McAdam, 2




air brick

A hollow or pierced brick built into a wall to allow the passage of air.




air bridge

A passage through which a ventilating current is conducted over an entry
or air course; an overcast. See also:air crossing




air bubble

See:air bell




air chamber

A vessel installed on piston pumps to minimize the pulsating discharge of
the liquid pumped. The chamber contains air under pressure and is fitted
with an opening on its underside into which some of the liquid from the
pump is forced upon the delivery stroke of the piston. The air acts as a
cushion to lessen the fluctuation of the liquid flow between the suction
and delivery strokes of the piston. Crispin


air change

a. The quantity of infiltration of ventilation air in cubic meters per
second divided by the volume of the room gives the number of so-called air
changes during a given interval of time. Tables of the recommended number
of such air changes for various rooms are used for estimating purposes.
b. The act of instituting a different pattern of air flow in a mine.




air channels

In a reverberatory furnace, flues under the hearth and fire bridge through
which air is forced to avoid overheating. Henderson




air circulation

a. A large volume of air, under compression, used in lieu of a liquid as a
medium to cool the bit and eject drill cuttings from a borehole.
Syn:air flush
b. The general process of moving air around the openings of a mine.
See also:air




air classification

a. In powder metallurgy, the separation of powder into particle-size
fractions by means of an airstream of controlled velocity; an application
of the principle of elutriation. ASM, 1
b. Sorting of finely ground minerals into equal settling fractions by
means of air currents. These are usually controlled through cyclones,
which deliver a coarse spigot product and a relatively fine vortical
overflow. See also:infrasizer
c. A method of separating or sizing granular or powdered materials, such
as clay, through deposition in air currents of various speeds. This
principle is widely used in continuous pulverizing of dry materials, such
as frit, feldspar, limestone, and clay. See also:air classifier;
air elutriator. Enam. Dict.




air classifier

An appliance for approx. sizing crushed minerals or ores by means of
currents of air. See also:air classification; air elutriator.
CTD




air cleaning

A coal-cleaning method that utilizes air to remove the dust and waste from
coal. Air cleaning requires that the coal contain less than 5% of surface
moisture as a rule. It is effective only in the coarse sizes (plus 10 to
28 mesh) and is best suited to coals having a sharply defined line between
coal and refuse material. Predrying to reduce the moisture content of the
coal ahead of the air treatment is not uncommon. It is a less expensive
and also a less accurate method of cleaning coal than the wet-cleaning
method. Kentucky




air compartment

An airtight portion of any shaft, winze, raise, or level used for
ventilation. BS, 8




air conditioning

The simultaneous control, within prescribed limits, of the quality,
quantity, temperature, and humidity of the air in a designated space. It
is essentially atmospheric environmental control. Control of only one or
two of these properties of the atmosphere does not constitute air
conditioning. The definition and correct usage require that the purity,
motion, and heat content of the air must all be maintained within the
prescribed limits. Hartman, 2




air-conditioning process

When conditioning is designed to perform only one or a limited number of
functions, then it should be so designated. Air-conditioning processes
include dust control, ventilation, dehumidification, cooling, heating, and
many others. See also:aftercooler; air receiver; compressed air;
duplex compressor; rotary compressor; turbocompressor. Hartman, 2




air-cooled blast-furnace slag

The material resulting from solidification of molten blast-furnace slag
under atmospheric conditions. Subsequent cooling may be accelerated by
application of water to the solidified surface. ASTM




air course

a. Ventilating passage underground. Pryor, 3
b. A passage through which air is circulated, particularly a long
passageway driven parallel to the workings to carry the air current.
See also:airway




air coursing

The system of colliery ventilation, introduced about 1760, by which the
intake air current was made to traverse all the underground roadways and
faces before passing into the upcast shaft. Nelson




air creep

Stain formed by air entering at edges of mica sheets and penetrating along
cleavage planes. Skow




air crossing

A bridge where a return airway passes over (overcast) or under (undercast)
an intake airway. It is generally constructed with concrete blocks,
structural steel, and/or sheet metal, and is made airtight to prevent
intermixing of the two air currents. The mining law requires an air
crossing to be so constructed as not to be liable to be damaged in the
event of an explosion. Syn:air bridge; bridge; overcrossing; overgate.
See also:overcast; undercast. Nelson




air current

a. The flow of air ventilating the workings of a mine. Syn:airflow;
air quantity. BS, 8
b. A body of air moving continuously in one direction. Jones, 1




air cushion

Air trapped in the bottom of a dry borehole by the rapid descent of a
tight string of borehole equipment. Syn:air block




air cyclone

Primarily a vessel for extracting dust from the atmosphere. Nelson




air decking

The use of air space or a void within a blast hole between an explosive
charge and inert stemming to enhance the shock wave detonation force.




air dome

A cylindrical or bell-shaped container closed at the upper end and
attached in an upright position above and to the discharge of a
piston-type pump. Air trapped inside the closed cylinder acts as a
compressible medium, whose expansion and contraction tends to reduce the
severity of the pulsations imparted to the liquid discharged by each
stroke of a pump piston. Syn:bonnet; pressure dome. CF:dome
Long




air door

A door erected in a roadway to prevent the passage of air. When doors are
erected between an intake and a return airway, they may be known as
separation doors. Syn:door; separation door; trapdoor. BS, 8




Airdox

A system for breaking down coal by which compressed air, generated locally
by a portable compressor at 10,000 psi (69.0 MPa), is used in a releasing
cylinder, which is placed in a hole drilled in the coal. Thus, slow
breaking results, with no flame, in producing a larger percentage of lump
coal than is made by using explosives. Its principal advantage is that it
may be used with safety in gaseous and dusty mines.
See also:compressed-air blasting


air drain

A passage for the escape of gases from a mold while the molten metal is
being poured. Standard, 2




air-dried

Said of minerals naturally dried to equilibrium with the prevailing
atmosphere. Pryor, 3




air-dried basis

An analysis expressed on the basis of a coal sample with moisture content
in approximate equilibrium with the surrounding atmosphere. BS, 4




air drift

a. An opening driven for ventilation purposes, often inclined and driven
in stone.
b. A drift connecting a ventilation shaft with the fan.




air drill

a. A small diamond drill driven by either a rotary or a
reciprocating-piston air-powered motor; used principally in underground
workings. Long
b. As used by miners, a percussive or rotary-type rock drill driven by
compressed air. CF:air rig




air-dry

a. Dry to such a degree that no further moisture is given up on exposure
to air. Most air-dry substances contain moisture that can be expelled by
heating them or placing them in a vacuum. Webster 3rd; Fay
b. Said of timber the moisture content of which is in approximate
equilibrium with local atmospheric conditions. CTD




air duct

a. Tubing that conducts air, usually from an auxiliary fan, to or from a
point as required in the mine. BS, 8
b. An air box, canvas pipe, or other air carrier for ventilation.
Hess




air elutriation

Method of dividing a substance into various particle sizes by means of air
currents. Bennett




air elutriator

An appliance for producing, by means of currents of air, a series of sized
products from a finely crushed mineral (e.g., for the paint or abrasive
industries). See also:air classification; air classifier. CTD




air endway

A narrow roadway driven in a coal seam parallel and close to a winning
headway chiefly for ventilation; it usually acts as a return and is
connected at intervals of 10 yd (9 m) or so to the headway by crosscuts.




air-float table

Shaking table in which ore is worked dry, air being blown upward through a
porous deck so as to dilate the material. Pryor, 1




airflow

See:air current




airflow-equalizing device

A flow-equalizing device that is fitted to tube breathing apparatus. There
are two kinds in general use, one consisting of a flexible, corrugated
rubber tube and the other a canvas fabric bag. On inspiration, air is
drawn partly from the equalizer, which is reduced in volume, and partly
from the tube. On expiration, the equalizer restores itself to its
original volume and in doing so draws air through the tube. Thus the air
is kept flowing very nearly in a continuous stream, and the wearer,
without the aid of bellows or rotary blower, experiences very little
resistance to breathing. Mason




airflow meter

An instrument that measures and provides readout of the flow of air in a
pipe or hose in cubic meters per second.




air flush

See:air circulation




air flushing

The circulation of air through the drilling apparatus during drilling to
cool the bit and to remove the cuttings from the hole. BS, 8




airfoil fan

A fan with an airfoil-shaped blade that moves the air in the general
direction of the axis about which it rotates. Strock, 2




air furnace

Malleable-iron furnace.
?€?ÚÀ kDICTIONARY TERMS:air gate a. Mid. An underground roadway used princi
[\B]air gate[\N]




airhammer

A tool in which a hammerhead is activated by means of compressed air. The
airhammer is called a jackhammer in coal mining and jackleg-hammer in
hardrock mining. The tool is used to drill blastholes to grade or take up
bottom or to advance a stope. Crispin




air heater

An appliance to warm the air as it enters the downcast shaft or intake
drift. In countries where the winter is very cold, nearly all mines are
equipped with air heaters of the oil-fired, gas-fired, or electric type.




air hoist

a. Hoisting machinery operated by compressed air. Fay
b. A small portable hoisting machine usually mounted on a column and
powered by a compressed air motor. Also called tugger. Long


airhole

a. A small excavation or hole made to improve ventilation by communication
with other workings or with the surface. See also:cundy
b. A venthole in the upper end of the inner tube of a double-tube core
barrel to allow air and/or water entrapped by the advancing core to
escape. Long
c. A void, cavity, or flaw in a casting or bit crown. Long




air horsepower

The rate at which energy is consumed, in horsepower or kilowatt units, in
moving air between two points.




air hp

Abbrev. for air horsepower.




airing

Operation in which air is blown through molten copper in a wire bar or
anode furnace. Sulfur is removed as SO, and impurities are slagged off.
Pryor, 3




air intake

a. The airway or airways through which fresh air is brought into a mine.
b. A device for supplying a compressor with clean air at the lowest
possible temperature.




air jig

A machine in which the feed is stratified by means of pulsating currents
of air and from which the stratified products are separately removed.
BS, 5




air lancing

a. Removing or cutting away loose material by means of compressed air,
using an air lance; airblasting. Henderson
b. In founding, a cleaning operation, as cleaning sand from molds and
castings, using an air lance; airblasting. Henderson
c. Opening passages for molten materials.




air leakage

a. The short-circuiting of air from intake to return airways (through
doors, stoppings, wastes, and old workings) without doing useful work in
flowing around the faces. The total air leakage is usually within the
range of 35% to 53% of that passing through the surface fan.
Nelson
b. The air that escapes from compressed-air lines by leakage from joints,
valves, hoses, etc.




air leg

a. A cylinder operated by compressed air, used for keeping a rock drill
pressed into the hole being drilled. Hammond
b. A device, incorporating a pneumatic cylinder, providing support and
thrust for a jackhammer. BS, 12




air-leg support

An appliance to eliminate much of the labor when drilling with handheld
machines. It consists of a steel cylinder and air-operated piston, the rod
of which extends through the top end of the cylinder and supports the
drilling machine. The air leg and machine can be operated by one worker.
Syn:pneumatic drill leg




air level

Eng. A level or airway (return airway) of former workings used in
subsequent deeper mining operations for ventilation.




air lift

An apparatus used for pumping water from wells either temporarily or for a
permanent water supply; for moving corrosive liquids such as sufuric acid;
for unwatering flooded mines; for elevating mill tailings, sands, and
slimes in cyanide plants; and for handling the feed to ball mills. In
operation, compressed air enters the eduction pipe and mixes with the
water. As the water and air rise, the air expands and is practically at
atmospheric pressure at the top of the discharge pipe. The efficiency of
the air lift is calculated on the basis of the foot-pounds of work done in
lifting the water, divided by the isothermal work required to compress the
air. Lewis




air-lift dredge

Dredge in which solids suspended in a fluid are lifted. By injecting air
into a submerged pipe beneath the water surface, the density of the fluid
column inside the pipe can be lessened, forcing the fluid column to rise
in the tubular pipe. Syn:airlift sampler




airlift sampler

See:air-lift dredge




air-line lubricator

See:line oiler




airline respirator

An atmosphere-supplying respirator in which the respirable-gas supply is
not designed to be carried by the wearer (formerly called supplied-air
respirator). ANSI




air lock

a. A casing at the top of an upcast shaft to minimize surface air leakage
to the fan. It consists of a large double casing enveloping the whole of
the upcast-shaft top and extending into the headgear. Some are fitted with
power-operated doors and allow high-speed winding with little leakage. A
modern light-alloy structure raised through spring-loaded attachments by
the top of the cage on ascending has proved efficient.
Syn:shaft casing
b. A system of doors arranged to allow the passage of workers or vehicles
without permitting appreciable airflow. BS, 8




airman

A worker who constructs brattices. Syn:brattice worker




air mat

A mat made of porous material, usually canvas, and used to subdivide and
distribute air in certain pneumatic-type flotation machines. Hess




air mover

A portable compressed-air appliance, which may be used as a blower or
exhauster. It converts the compressed air into a large induced volume of
moving air. The compressed air is fed through a side inlet and is expanded
at a high velocity through an annular orifice. It is useful for emergency
ventilation in workings where auxiliary fans cannot be installed.
Syn:injector; static air mover. See also:auxiliary ventilation
Nelson




air-operated winch

A small, compressed-air drum haulage or hoist used for lifting, dragging,
or skidding work in mines. With capacities ranging from 660 to 4,400 lb
(300 to 2,000 kg), these winches have powerful piston motors and are
capable of continuous operation. They are easy to move from job to job and
are used for shaft sinking and moving wagon drills at quarry and opencast
operations. Nelson


air photograph

See:aerial photograph




air pit

See:air shaft




airplane-strand wire rope

A small 7- or 19- wire galvanized strand made from plow steel or
crucible-steel wire. Hunt




air-power-operated mine door

Mine doors help to keep the air flow in shafts and mine working areas
constant. In cases of explosions, doors "give" to relieve the pressure,
then close automatically. The doors are mobile and can be set up in any
location. They are opened and closed by a compressed-air cylinder and are
designed to be used where haulage equipment operates on a trolley wire.
Best, 1




air pressure

a. For rock drills, the air pressure ranges from 70 to 90 psi (480 to 620
kPa), the most economical pressure for such machines being from 90 to 95
psi (620 to 655 kPa), when high drilling speed is attained.
Hammond
b. To operate the percussive tool and to flush the hole of cuttings,
surface mounted drills use 690 to 1,725 kPa air pressure.
Cumming, 2




air-pressure drop

The pressure lost or consumed in overcoming friction along an airway.




air propeller

A rotating set of blades designed to impart momentum to an air mass.




air pump

A pump for exhausting air from a closed space or for compressing air or
forcing it through other apparatus. CF:vacuum pump




air-purifying respirator

A respirator in which ambient air is passed through an air-purifying
element that removes the contaminants. Air is passed through the
air-purifying element by means of the breathing action or by a blower.
ANSI




air quantity

The amount of air flowing through a mine or a segment of a mine, in cubic
meters per second. Air quantity is the product of the air velocity times
the cross-sectional area of the airway. See also:air current
Syn:air volume




air ramming

A method of forming refractory shapes, furnace hearths, or other furnace
parts by means of pneumatic hammers. Harbison-Walker




air receiver

A vessel into which compressed air is discharged to be stored until
required. See also:air-conditioning process




air-reduction process

See:roasting and reaction process




air regulator

An adjustable door installed in permanent air stoppings or in an airway
without a stopping to control ventilating current.




air requirements

The quantity of air required by law or practical considerations to
maintain adequate ventilation of a mine. This quantity will depend on (1)
the length of face room in production, (2) the average distance from the
shafts to the faces, (3) the gas emission rate, (4) the depth of the
workings, and (5) the volumetric efficiency of the mine ventilation.
See also:air volume; ventilation planning.




air rig

A drill machine powered by an airdriven motor. CF:air drill
Long




air rod puller

See:rod puller




air rotary drilling

Drilling technique that utilizes compressed air to lift the cuttings up
the borehole and to cool the bit. Used when possible for environmental
monitoring, because no drilling fluids are introduced into the formation.
Feasible only in consolidated or semiconsolidated formations.
Driscoll




air-sand process

See:Fraser's air-sand process




air seal

A method for the prevention of the escape of warm gases from the entrance
or exit of a continuous furnace, or tunnel kiln, by blowing air across the
opening. Dodd




air separation

In powder metallurgy, the classification of metal powders into particle
size ranges by means of a controlled airstream. Rolfe




air separator

A machine for the size classification of the fine ceramic powders, such as
china clay; the velocity of an air current controls the size of particle
classified. Dodd




air set

a. The property of a material to develop high strength when dried; e.g.,
air-setting mortars. ARI
b. In a material such as a castable refractory, refractory mortar, or
plastic refractory, the ability to harden without the application of heat.
AISI




air shaft

A shaft used wholly or mainly for ventilating mines, for bringing fresh
air to places where miners are working, or for exhausting used air. It may
be used as an intake (downcast) shaft or a return (upcast) shaft.
See also:downcast; upcast. Syn:air pit




air shooting

In seismic prospecting, a technique of applying a seismic pulse to the
ground by detonating explosive charges in the air. AGI




air shot

A shot prepared by loading (charging) in such a way that an airspace is
purposely left in contact with the explosive for the purpose of lessening
its shattering effect. Fay




air shrinkage

The volume decrease that a clay undergoes in drying at room temperature.




air-slaked

Slaked by exposure to the air; as lime. Standard, 2




air-slaking

Exposure of quicklime to the atmosphere to give slow hydration.
Pryor, 3




air slit

York. A short heading driven more or less at right angles to and between
two headings or levels for ventilation. See also:stenton




air slug

A mass of air under compression entrapped in the liquid circulated through
a borehole drill string or a liquid-piping system. Long




air sollar

A compartment or passageway carried beneath the floor of a heading or of
an excavation in a coal mine for ventilation. See also:sollar




air-space ratio

The ratio of a volume of water that can be drained from a saturated soil
under the action of force of gravity to a total volume of voids.
ASCE




air-sparged hydrocyclone

A separator consisting of two concentric right-vertical tubes, a
conventional cyclone header at the top, and a froth pedestal at the
bottom. The inner tube is a porous-wall tube. The slurry is fed
tangentially through the cyclone header to develop a radial swirl flow.
Air is sparged through the jacketed, inner porous tube wall and is sheared
into small bubbles by the swirl flow. Hydrophobic coal particles in the
slurry attach to the air bubbles and report as overflow product. The
hydrophilic refuse particles remain wetted and report as underflow
product.




air split

The division of the main current of air in a mine into two or more parts.
See also:split




air stack

A chimney formerly used to ventilate a mine.




air stain

Gas trapped beneath mica cleavage surfaces in flattened pockets, tiny
bubbles, or groups of closely spaced bubbles. Skow




air starter

A starter used on large coal haulers that permits the elimination of all
batteries except the 6-V units for the headlights. These starters are
operated by compressed air supplied at 100 psi (690 kPa) from a storage
tank on the tractor. Trucks can stand idle for 4 or 5 days and there is
still enough air in the tanks to start the engines. Coal Age, 3




air-stowing machine

The machine used for blowing the stone chippings into the waste area in
pneumatic stowing. It consists of a steel paddle wheel revolving in an
adjustable casing. Stowing dirt is fed continuously from a hopper to the
machine, which in turn blows the material through pipes 5 to 6 in (13 to
15 cm) in diameter into the waste area. See also:pneumatic stowing
Nelson




air streak

In mica, a series of air inclusions connected (or nearly connected) to
form a relatively long, thin streak. Also known as silver streak.
Skow




air survey

In mining, a check on ventilation, gas, and dust in a mine.
Pryor, 3




air-swept ball mill

See:ball mill


air-swept mill

A tumbling mill used in dry grinding, from which finished material is
removed by means of regulated air currents that can be so controlled as to
produce a closed circuit. Pryor, 1




air swivel

A device similar to a water swivel but designed to conduct air under
compression into a rotating drill stem when air instead of a liquid is
used as an agent to flush drill cuttings out of a borehole.
CF:water swivel




air table

A shaking table used when water is scarce to effect gravity concentration
of sands. Air is blown upward through a porous deck, over which a layer of
finely crushed ore passes. The heavy and light minerals stratify and
gravitate to separate discharge zones. Syn:pneumatic table
Pryor, 1




air-track drill

A heavy drilling machine for quarry or opencast blasting. It has
continuous tracks and is operated by independent air motors. It tows its
rotary compressor and drills holes 3 in or 4 in (7.6 cm or 10.2 cm) in
diameter at any angle, but it is chiefly used for vertical holes up to 80
ft (24.4 m) in depth. Nelson




air transport

A method employed in some mines in which material is transported and
stowed pneumatically through pipelines. Stoces




air trunk

A large pipe or shaft for conducting air, such as for ventilation or to a
furnace. Fay




air tub

The cylinder on a blowing engine that pumps a blast of wind or air.
Fay




air turbolamp

A lamp coupled to the compressed air mains, which may be at any pressure
between 275 kPa and 700 kPa. It consumes 0.025 m3 /s of free air.
The electrical power is produced by a small turboalternator with a
six-pole permanent magnet rotor.




air valve

The valve that controls the alternate admission and release of compressed
air to each cell of a Baum-type washbox. BS, 5




air velocity

The rate of motion of air in a given direction; in mine ventilation it is
usually expressed in meters per second. This is usually measured
conducting a vane anemometer traverse over a selected cross section, the
area of which is also measured.




air vessel

A small air chamber fixed to the pipeline on the discharge side of a
reciprocating pump that acts as a cushion to minimize the shock produced
by the pulsations of the pump. Nelson




airveyor

A device for handling dusty materials, built on the principle of a
pneumatic cleaner. The system used is a suction system, whereby the
material (soda ash, salt cake, cement, or powdered lime) is drawn from the
car through a flexible hose into a vacuum tank designed to recover a large
percentage of the dust floating in the air. Hess




air-void ratio

The ratio of the volume of air space to the total volume of voids in a
soil mass. ASCE




air volume

In mining, the quantity (Q) of air flowing in cubic meters per second. It
is obtained by multiplying the average velocity (V) in meters per second
by the area (A) of the airway in square meters; i.e., Q = AV.
See also:air requirements; air quantity.




air washer

Air washers make use of water sprays or cooling coils for evaporative and
sensible cooling of mine air. Their use has largely been limited to
shallow coal mines in the United States, where it is desirable to reduce
the dry-bulb temperature of the intake air during the hot summer months to
prevent slaking of the roof due to excessive expansion. An air washer is
essentially a heat exchanger and is similar to the type of unit employed
for heat transfer with refrigeration or evaporative-cooling systems.




air wave

The acoustic-energy pulse transmitted through the air as a result of a
pressure (sound) source; e.g., explosion, near-surface seismic shot, or
supersonic aircraft. AGI




airway

Any underground gallery or passage through which a portion of the
ventilation passes; i.e., the air is carried. Syn:air course;
wind road. BCI




Airy hypothesis

A concept of the mechanism of isostasy, proposed by George Bedell Airy,
that postulates an equilibrium of crustal blocks of the same density but
of different thickness; thus the topographically higher mountains would be
of the same density as other crustal blocks but would have greater mass
and deeper roots. CF:Pratt hypothesis




Ajax

A high-strength, high-density, gelatinous permitted explosive having good
water resistance; used for dry and wet conditions both in rock and in the
breaking of hard coal. See also:Polar Ajax




ajkaite

A pale-yellow to dark reddish brown, sulfur-bearing fossil resin found in
brown coal. Also spelled ajkite. AGI




ajutage

Roman term designating size of water delivery pipes and outlet spouts.
Syn:adjutage


akaganeite

A tetragonal mineral, ferric oxyhydroxide beta-FeO(OH,Cl) ; rust colored;
occurs in soils.




akhtenskite

A hexagonal mineral (epsilon-MnO2 ), trimorphous with pyrolusite
and ramsdellite. See:pyrolusite




Akins' classifier

Used for separating fine-size solids from coarser solids in a wet pulp;
consists of an interrupted-flight screw conveyor operating in an inclined
trough.




akrochordite

A monoclinic mineral, Mn4 Mg(AsO4 )2 .4H2 O ;
forms reddish-brown rounded aggregates.




aksaite

An orthorhombic mineral, MgB6 O7 (OH)6 .2H2 O.




alabandite

An isometric mineral, manganese sulfide, MnS ; iron-black; in epithermal
vein deposits; an ore of manganese. Formerly called alabandine.
Syn:manganblende; manganese glance.




alabaster

A massive form of gypsum; very fine grained; commonly snow-white and
translucent but may be delicately shaded or tinted with light-colored
tones. Because of its softness, it can be easily carved and polished.
Widely used for ornamental purposes. Chemically it is CaSO4 .2H
2 O . It is a beautifully banded form of stalagmitic calcite
occurring in Algeria and in Egypt. Syn:oriental alabaster; onyx marble.
CMD




aladzha

Impure ozokerite containing an admixture of country rocks and found in the
region of the Caspian Sea. Tomkeieff




alamosite

A monoclinic mineral, PbSiO3 . Syn:lead silicate;
lead metasilicate.




alaskite

In the United States, a commonly used term for a granitic rock containing
few, if any, dark minerals. The term is used to designate granitoid rocks
in which quartz constitutes 20% to 60% of the felsic minerals and in which
the ratio of alkali feldspar to total feldspar is greater than 90%; i.e.,
the equivalent of alkali granite. Alaskite is a commercial source of
feldspar near Spruce Pine, NC. CF:aplogranite




albertite

A dark brown to black asphaltic pyrobitumen with conchoidal fracture
occurring as veins 1 to 16 ft (0.3 to 4.9 m) wide in the Albert Shale of
Albert County, NB, Can. It is partly soluble in turpentine, but
practically insoluble in alcohol. It was earlier called albert coal.
AGI




albert shale

An early name for albertite. Tomkeieff




albite

a. A triclinic mineral, NaAlSi3 O8 ; feldspar group, with up
to 10 mol % CaAl replacing NaSi; a member of the plagioclase and the
alkali feldspar series; prismatic cleavage; a common rock-forming mineral
in granite, intermediate to felsic igneous rocks, low-temperature
metamorphic rocks, and hydrothermal cavities and veins; can be used as a
glaze in ceramics.
b. The pure sodium-feldspar end member in the plagioclase series.
Syn:sodium feldspar; white feldspar; white schorl.




albite-epidote-amphibolite facies

The set of metamorphic mineral assemblages (facies) in which basic rocks
are represented by hornblende + albite + epidote. Equivalent to Eskola's
epidote-amphibolite facies, it is of uncertain status, transitional
between the greenschist facies and the amphibolite facies. It is generally
believed to be favored by the higher pressures of regional metamorphism.
AGI




albite porphyrite

See:albitite




albitite

A porphyritic igneous rock, containing phenocrysts of albite in a
groundmass chiefly consisting of albite. Muscovite, garnet, apatite,
quartz, and opaque oxides are common accessory minerals.
Syn:albitophyre; albite porphyrite. AGI




albitization

Introduction of, or replacement by, albite, usually replacing a more
calcic plagioclase. AGI




albitophyre

See:albitite




albond

A kaolinitic clay found in Dorsetshire, England. It is used as a
low-percentage addition to natural molding sands. Osborne




alchemy

The immature chemistry of the Middle Ages, characterized by the pursuit of
the transmutation of base metals into gold, and the search for the
alkahest and the panacea. Standard, 2




alcohol

C2 H5 OH ; made from grain. Not to be confused with methyl
hydroxide or methanol. Syn:ethanol


alexandrine sapphire

Incorrect name for alexandritelike sapphire; also for so-called synthetic
alexandrite.




alexandrite effect

The property of some chrysoberyl and other minerals and stones to appear
green in sunlight, but red under incandescent illumination.




alexandritelike tourmaline

See:chameleonite




alexeyevite

A waxlike resin from Kaluga, Russ, which resembles compact turf. Also
spelled alexjejevite.




algae

Photosynthetic, almost exclusively aquatic, plants of a large and diverse
division (Algae) of the thallophytes, including seaweeds and their
fresh-water allies. It ranges in size from simple unicellular forms to
giant kelps several meters long, and displays extremely varied life-cycles
and physiological processes, with, e.g., different complexes of
photosynthetic pigments. Algae range from the Precambrian. An individual
plant is called an alga. AGI




algal

Of, pertaining to, or composed of algae. AGI




algal coal

Coal composed mainly of algal remains, such as Pila, Reinschia, etc. Also
called boghead coal. Tomkeieff; AGI




algal limestone

A limestone composed largely of the remains of calcium-carbonate-producing
algae, or one in which such algae bind together the fragments of other
calcium-carbonate-producing forms. AGI




algal reef

An organic reef in which algae are or were the principal organisms
producing calcium carbonate, e.g., off the coast of Bermuda. The reefs may
be up to 10 m high and more than 15 m across. AGI




algal stromatolite

See:stromatolite




algarite

A general term for a bitumen derived from algae. Tomkeieff




alga sapropel

Equivalent to peat of the humic coal series. AGI




Algerian onyx

See:oriental alabaster




alginate

Designates the characteristic maceral of boghead coal. In reflected light
it is very difficult to recognize the cellular structure of the algae. The
reflecting power of the maceral is much weaker than that of vitrinite and
is also weaker than that of sporinite in coals of low rank. In transmitted
light, alginite sometimes shows structure (of colonies of algae). The
color is yellow to orange. Alginite is best recognized by luminescent
microscopy; it shows marked luminescence of varying color--silvery blue,
green, yellowish brown. The humic constituents either are not luminescent
or show a different kind of luminescence to the alginite. Syn:algite
IHCP




algite

The constituent petrological unit, or maceral, of algal material present
in considerable quantity in algal or boghead coal. See also:alginate
AGI




algodonite

a. Arsenide of copper occurring as a white incrustation in the Algodona
silver mine, Chile. CTD
b. An orthorhombic mineral, Cu6 As ; pseudohexagonal.




Algoman orogeny

Orogeny and accompanying granitic emplacement that affected Precambrian
rocks of northern Minnesota and adjacent Ontario about 2.4 billon years
ago; it is synonymous with the Kenoran orogeny of the Canadian
classification. AGI




alidade

a. In mine surveying, a movable arm used to read horizontal angular
distances. Pryor, 3
b. A device having a level bubble combined with a quarter or a half circle
graduated in degrees that is used by drillers to determine the inclination
of a drill stem and/or borehole at the collar of the borehole. Also called
angle level; angle rule; clinometer; clinometer rule. Long
c. An instrument used in planetable surveying, consisting of a telescope
or sighting device pivoted to swing through a vertical graduated arc atop
a vertical stand attached to a steel rule, one edge of which is parallel
with the sight line of the telescope. Long
d. Sometimes incorrectly used as a syn. for transit; theodolite.
Long
e. A rule equipped with simple or telescopic sights, used for determining
the directions of objects, specif., a part of a surveying instrument
consisting of a telescope or other sighting device, with index and reading
or recording accessories. AGI
f. A surveying instrument used with a planetable for mapping; e.g.,
peep-sight alidade and telescopic alidade. AGI




alien filling

Filling material brought from the surface or from some place other than
the mine. Stoces




align

a. To position a drill so that its drill stem is centered on a point and
parallel to a predetermined angle and compass direction. Also called line
in; lineup. Long
b. To reposition a drill and bring its drill stem over the center and
parallel with a newly collared drill hole. Long




alignment

a. The planned direction of a tunnel or other roadway driven irrespective
of coal seam or orebody structure; the planned direction of longwall
panels or face lines. Nelson
b. Formation or position in line, or, more properly, in a common vertical
plane. Seelye, 2
c. The laying out of the axis of a tunnel by instrumental work.
Stauffer
d. See:coplaning
e. In railway or highway surveying, the ground plan, showing the alignment
or direction of the route to be followed, as distinguished from a profile,
which shows the vertical element. Seelye, 2
f. The act of laying out or regulating by line; adjusting to a line.


alinement clamp

A setscrew-equipped, universal-type clamp from one side of which a slotted
angle-iron wand, about 18 in (45.7 cm) long, extends outward from a
clamping device at 90 degrees . May be made to fit any size drill rod and
is used in pairs, leapfrog fashion, to orient successive rods in a
specific compass direction as these are lowered into a borehole being
surveyed by the acid-bottle method. By this means, the bearing and
inclination of a drill hole may be determined in formation or under
conditions where a Maas- or other-type magnetic compass cannot be used.
Long




aliphatic

Of, relating to, or derived from fat; fatty; acyclic. Applied to a large
class of organic compounds characterized by an open-chain structure and
consisting of the paraffin, olefin, and acetylene hydrocarbons and their
derivatives (as the fatty acids). Webster 3rd




alipite

A discredited term referring to massive apple-green, hydrated
magnesium-nickel silicate similar to genthite.




alisonite

A massive, deep indigo-blue copper-lead sulfide, Cu2 S.PbS . It
contains 53.63% copper and 28.25% lead. Tarnishes quickly. Hess




Aliva concrete sprayer

A compressed-air machine for spraying concrete on the roof and the sides
of mine roadways. Used in coal mines for the fireproofing of roadways, for
reducing air leakages, and for spraying tunnels supported by roof bolts.
See also:guniting; gunite. Nelson




alive

Said of coal when it makes a rustling sound as it bursts, cracks, and
breaks off while under pressure. The rising of methane from the coal
causes a similar sound. CF:dead




alkali

a. Any strongly basic substance, such as a hydroxide or carbonate of an
alkali metal (e.g., sodium, potassium). Plural: alkalies. Adj. alkaline;
alkalic. Said of silicate minerals that contain alkali metals but little
calcium; e.g., the alkali feldspars. AGI
b. Any substance having marked basic properties; i.e., being capable of
furnishing to its solution or other substances the hydroxyl ion, OH (super
-) . Stokes




alkali bentonite

A bentonite containing easily exchangeable alkali cations and having
original properties that are not permanently destroyed by the action of
sulfuric acid, but can be restored by treatment with an alkali salt
followed by regulated dialysis. This group includes Wyoming-type bentonite
and other similar bentonites. Davis




alkalic

a. Said of an igneous rock that contains more alkali metals than is
considered average for the group of rocks to which it belongs. AGI
b. Said of an igneous-rock series that contains more sodium and/or
potassium than is required to form feldspar with the available silica.
AGI
c. Said of an igneous-rock series containing less than 51% silica when the
weight percentages of CaO and of K2 O + Na2 O are equal.
AGI
d. Said of an igneous rock belonging to the Atlantic suite. Syn:alkali;
alkaline. AGI




alkalic feldspar

See:alkali feldspar




alkali earth

One of a group of elements (Group II) forming divalent cations; esp.
calcium, strontium, and barium, but also includes beryllium, magnesium,
and radium.




alkali feldspar

a. Those feldspars composed of mixtures or crystal solutions of potassium
feldspar, KAlSi3 O8 , and sodium feldspar, NaAlSi3 O
8 , with little or no calcium feldspar, CaAl2 Si2 O
8 .
b. The subgroup of the feldspar group including albite, anorthoclase,
microcline, orthoclase, and sanidine. Syn:alkalic feldspar
CF:plagioclase




alkali flat

A level area or plain in an arid or semiarid region, encrusted with alkali
salts that became concentrated by evaporation and poor drainage; a salt
flat. See also:playa




alkali garnet

A general term for members of the sodalite group that are closely related
crystallographically and chemically to the true garnets. English




alkali granite

a. A coarse-grained, plutonic rock carrying free quartz and alkali
feldspar. CMD
b. A granitoid rock with accessory sodic amphibole or sodic pyroxene.




alkali-lime series

Igneous rocks that contain soda-lime (plagioclase) feldspars. Hess




alkali metal

A metal in group IA of the periodic system; namely, lithium, sodium,
potassium, rubidium, cesium, and francium. They form strong alkaline
hydroxides; hence, the name. Syn:alkaline metal




alkalimeter

a. An apparatus for measuring the strength or the amount of alkali in a
mixture or solution. Webster 3rd
b. An apparatus for measuring the amount of carbon dioxide (as that
liberated from a weighed sample of carbonate-containing material by
reaction with acid). Webster 3rd




alkaline

Adj. of alkali. See:alkalic




alkaline-earth bentonite

A bentonite containing easily exchangeable alkaline-earth cations and,
either before or after acid treatment, capable of being made to assume
properties of an alkali bentonite by treatment with an alkali salt
followed by regulated dialysis.




alkaline-earth metal

A metal in group IIA of the periodic system; namely, beryllium, magnesium,
calcium, strontium, barium, and radium; so called because the oxides or
earths of calcium, strontium, and barium were found by the early chemists
to be alkaline in reaction. ASM, 1


alkaline metal

See:alkali metal




alkalinity

The extent to which a material exhibits the property of yielding hydroxyl
ions in a water solution. See also:pH




alkali soil

A saline soil having 15% or more exchangeable sodium.




alkali subbentonite

A bentonite containing easily replaceable alkali bases but having original
properties that are destroyed by acid treatment. Davis




alkane

A member of the paraffin series, such as methane, ethane, etc.
Pryor, 3




alkene

A member of the hydrocarbon group series (CnH2 n); e.g., ethylene,
propylene. Pryor, 3




alkinite

A discredited term referring to a compound of lead, copper, bismuth, and
sulfur.




alkyne

One of a group of organic compounds containing a carbon-to-carbon triple
bond; e.g., acetylene, allylene. Also spelled alkine.
McGraw-Hill, 1




allactite

A monoclinic mineral, Mn7 (AsO4 )2 (OH)8 ;
vitreous; resembles the axinites. Also spelled allaktit.




allagite

A heavy dull-red or green altered carbonated rhodonite. Syn:diaphorite
Fay




allanite

A monoclinic mineral, 2[(Ca,Y,Ce)2 (Fe,Al)3 O(OH)(Si2
O7 )(SiO4 )] ; epidote group; massive, pitchy, slightly
radioactive, and metamict; a minor accessory in felsic igneous rocks and
pegmatites. Formerly called orthite; cerine; bucklandite; treanorite.
Syn:yttro-orthite




allargentum

A mineral, Ag1-x Sbx with x=0.09 to 0.16.




allcharite

Former name for a variety of goethite.




alleghanyite

A monoclinic mineral, Mn5 (SiO4 )2 (OH)2 ;
humite group; dimorphous with ribbeite; in skarns.




allemontite

A mixture of stibarsen, SbAs , and arsenic or antimony.
Syn:arsenical antimony




Allen cone

A conical tank used in mineral flotation to separate sand from slime using
a float-controlled spigot on peripheral overflow.
See also:cone classifier




Allen-O'Hara furnace

A horizontal, double-hearth furnace for calcining sulfide ores.
Fay




allevardite

See:rectorite




alley stone

See:aluminite




alliaceous

Said of minerals that have an odor of garlic when rubbed, scratched, or
heated; e.g., arsenical minerals.




alligator

a. See:safety clamp
b. Any of several types of machines for metalworking, rock crushing, etc.,
in which work is accomplished by two massive jaws, one or both of which
move as, e.g., alligator shears (preferably, lever shears) or an alligator
crusher (preferably, lever crusher). Henderson
c. A prolonged, steel hingelike device by means of which the abutting ends
of a flat drive belt can be fastened or laced together. Long


all-mine pig

Iron smelted entirely from raw ore. Standard, 2




allochem

A collective term introduced by Folk (1959) for one of several varieties
of discrete and organized carbonate aggregates that serve as the coarser
framework grains in most mechanically deposited limestones, as
distinguished from sparry calcite (usually cement) and carbonate-mud
matrix (micrite). Important allochems include silt-, sand-, and
gravel-size fragments torn up and reworked from the deposit; ooliths;
pellets; lumps; and fossils or fossil fragments (carbonate skeletons,
shells, etc.). Syn:allochemical




allochemical

See:allochem




allochroite

a. A calcium-chromium garnet. Fay
b. A reddish brown variety of andradite garnet.




allochromatic

a. Descriptive of crystals that exhibit electrical conductivity under the
influence of light. Hess
b. A gem stone with a coloring agent extraneous to its chemical
composition. Opposite of idiochromatic. Hess
c. Color produced by a chromophore that is not essential to mineral
composition.




allochromatic mineral

Mineral that would be colorless if chemically pure, but which commonly
exhibits a range of colors due to the presence of small quantities of one
or more coloring elements. Chief among these elements are those having
atomic numbers 22 to 29; namely, titanium, vanadium, chromium, manganese,
iron, cobalt, nickel, and copper. Corundum, beryl, spinel, and quartz are
examples of allochromatic gemstones. See also:idiochromatic mineral
Anderson




allochthon

a. A mass of rock that has been moved from its place of origin by tectonic
processes, as in a thrust sheet or nappe. Many allochthonous rocks have
been moved so far from their original sites that they differ greatly in
facies and structure from those on which they now lie. Ant. autochthon.
Syn:allochthonous
b. A mass of redeposited sedimentary materials originating from distant
sources. AGI




allochthonous

a. Originated by Gumbel and applied to rocks, the dominant constituents of
which have not been formed in place. CF:autochthonous
Holmes, 1
b. Coal formation according to the drift theory. Nelson
c. Formed or produced elsewhere than in its present place; of foreign
origin, or introduced. The term is widely applied; e.g., to coal or peat
that originated from plant material transported from its place of growth,
or to an allochthon on a low-angle thrust fault. The term is similar in
meaning to allogenic, which refers to constituents rather than whole
formations. Ant. autochthonous. See also:allochthon




allochthonous coal

Coal originating from accumulations of plant debris that have been
transported from their place of growth and deposited elsewhere. The debris
can be differentiated as coming from near or from far, and likewise
whether it represents recent (dead or still living) or already fossilized
material. Syn:drift coal
AGI; Tomkeieff




allochthonous peat

Drift peat of lacustrine character. It is subdivided into Gyttja type and
Dry type. Tomkeieff




alloclasite

A monoclinic mineral (Co,Fe)AsS ; steel gray; dimorphous with glaucodot.
Formerly called alloclase.




alloclastic breccia

See:volcanic breccia




allogenic

Generated elsewhere; applied to those constituents that came into
existence outside of, and previously to, the rock of which they now
constitute a part; e.g., the pebbles of a conglomerate. CF:authigenic
Holmes, 2




allogonite

See:herderite




allomeric

Of the same crystalline form but of different chemical composition.
Syn:isomorphous




allomorph

a. Syn:paramorph (obsolete); pseudomorph. AGI
b. A polymorph or dimorph. Adj. allomorphous.




allomorphism

Changes produced in minerals without gain or loss of components; e.g., the
change from kyanite to sillimanite. See also:paramorphism




allomorphite

Obsolete term for barite, esp., pseudomorphous after anhydrite.




allomorphous

Of the same chemical composition but of different crystalline form.
CF:allomeric




allopalladium

a. A nearly silver-white palladium, found in hexagonal plates in the Harz
Mountains, Germany. Fay
b. Former name for stibiopalladinite.
c. Palladium crystallizing in the hexagonal system (as opposed to
isometric palladium).




allophane

a. Al2 O3 .SiO2 .nH2 O . A clay mineral
composed of hydrated aluminosilicate gel of variable composition; P (sub
2) O5 may be present in appreciable quantity. Syn:riemannite
McGraw-Hill, 1
b. A mineral gel, amorphous hydrous aluminum silicate; soft; has pale
tints; in soils developed from volcanic glass and ash. It changes from
glassy to earthy upon dehydration.


allophanite

An obsolete syn. of allophane. AGI




allophanoids

Clays of the allophane, halloysite, and montmorillonite groups.
English




allothimorph

A constituent of a metamorphic rock which, in the new rock, has not
changed its original crystal outlines.




allotriomorphic

See:xenomorphic




allotriomorphic-granular

See:xenomorphic




allotropic

Applied by Berzelius to those substances that exist in two or more forms,
such as diamond and graphite. See also:polymorphism




allotropism

See:allotropy




allotropy

a. The existence of a substance, esp. an element, in two or more different
modifications usually in the same phase, such as different crystalline
forms of carbon, iron, phosphorus, and sulfur. Webster 3rd
b. Polymorphism in a chemical element; e.g., isometric and hexagonal
carbon (diamond and graphite), monoclinic and orthorhombic sulfur
(rosickyite and sulfur). An allotrope is one of the crystal forms.
Syn:allotropism




allowable bearing value

The maximum pressure that can be permitted on foundation soil giving
consideration to all pertinent factors, with adequate safety against
rupture of the soil mass or movement of the foundation of such magnitude
that the structure is impaired. Also called allowable soil pressure.
ASCE




allowable pile-bearing load

The maximum load that can be permitted on a pile with adequate safety
against movement of such magnitude that the structure is endangered.
ASCE




allowable stress

If a member is so designed that the maximum stress as calculated for the
expected conditions of service is less than some certain value, the member
will have a proper margin of security against damage or failure. This
certain value is the allowable stress, of the kind, and for the material
and condition of service in question. The allowable stress is less than
the "damaging stress" because of uncertainty as to the conditions of
service, nonuniformity of material, and inaccuracy of stress analysis. The
margin between the allowable stress and the damaging stress may be reduced
in proportion to the certainty with which the conditions of service are
known, the intrinsic reliability of the material, the accuracy with which
the stress produced by the loading can be calculated, and the degree to
which failure is unattended by danger or loss. CF:factor of safety
Syn:working stress




alloy

A substance having metallic properties, and composed of two or more
chemical elements, of which at least one is a metal. ASM, 1




alloyage

The act or process of alloying; specif., in minting, of alloying the
precious metals with baser ones to form a harder alloy.
Standard, 2




alloy sludger

A laborer who salvages sludge from furnace pots for use in recovery of
metals. Also called sludger. DOT




alloy system

All the alloys that can be made by mixing two metals from a binary alloy
system, three metals from a ternary alloy system, and so on. The limits of
temperature and composition within which the constituents in a system are
stable are represented by the constitutional diagram. CTD




alluaudite

a. A monoclinic mineral, Na,Ca)Fe+2 (Mn,Fe+2 ,Fe (super
+3) ,Mg)2 (PO4 )3 ; alluaudite group; forms a series
with ferroalluaudite; in pegmatites.
b. The mineral group alluaudite, caryinite, ferroalluaudite, hagendorfite,
maghagendorfite, and varulite.




alluvia

Seldom-used plural of alluvium. AGI




alluvial

a. Said of a placer formed by the action of running water, as in a stream
channel or alluvial fan; also said of the valuable mineral, e.g., gold or
diamond, associated with an alluvial placer. AGI
b. Pertaining to or composed of alluvium, or deposited by a stream or
running water; e.g., an alluvial clay or an alluvial divide. AGI




alluvial clay

A clay that has been deposited by water on land, usually in association
with rivers or streams. ACSB, 1




alluvial cone

An alluvial fan with steep slopes; it is generally higher and narrower
than a fan, and is composed of coarser and thicker material believed to
have been deposited by larger streams. The term is sometimes used
synonymously with alluvial fan. CF:alluvial fan
dry delta; wash. AGI




alluvial deposit

See:alluvium


alluvial fan

A low, outspread, gently sloping mass of loose rock material, shaped in
plan view like an open fan or a segment of a cone; deposited by a stream
(esp. in a semiarid region) at the place where it issues from a narrow
mountain valley upon a plain or broad valley, or where a tributary stream
is near or at its junction with the main stream, or wherever a
constriction in a valley abruptly ceases or the gradient of the stream
suddenly decreases; it is steepest near the mouth of the valley where its
apex points upstream, and it slopes gently and convexly outward with
gradually decreasing gradient. CF:alluvial cone; bajada. Syn:fan;
detrital fan; talus fan; dry delta. AGI




alluvial flat

A small alluvial plain bordering a river, on which alluvium is deposited
during floods. CF:alluvial plain




alluvial mining

The exploitation of alluvial deposits by dredging, hydraulicing, or drift
mining. See also:placer mining




alluvial ore deposit

See:placer




alluvial plain

A level or gently sloping tract or a slightly undulating land surface
produced by extensive deposition of alluvium, usually adjacent to a river
that periodically overflows its banks; it may be situated on a flood
plain, a delta, or an alluvial fan. CF:alluvial flat
river plain; bajada. AGI




alluvial slope

A surface underlain by alluvium, which slopes down and away from the sides
of mountains and merges with a plain or a broad valley floor; an alluvial
surface that lacks the distinctive form of an alluvial fan or a bajada.
See also:bajada




alluvial tin

Stream tin, or cassiterite pebbles in the gravel along the courses of
valleys and rivers on the bedrock. Generally, the purest tin ore.
See:stream tin




alluvial values

In placer mining, the minerals recoverable from the alluvium. These
include cassiterite, gold, diamond, gemstones, zirconia, rutile, monazite,
and platinum. Pryor, 3




alluviation

a. The deposition or formation of alluvium or alluvial features (such as
cones or fans) at places where stream velocity is decreased or streamflow
is checked; the process of aggradation or of building up of sediments by a
stream along its course, or of covering or filling a surface with
alluvium. AGI
b. A hydraulic effect on solids suspended in a current of water, whereby
the coarsest and heaviest particles are the first to settle out, and the
finest muds the last, as gradient or velocity of a stream is decreased.
AGI




alluvion

See:alluvium




alluvium

a. A general term for clay, silt, sand, gravel, or similar unconsolidated
detrital material, deposited during comparatively recent geologic time by
a stream or other body of running water, (1) as sediment in the bed of the
stream or on its flood plain or delta, (2) as a cone or fan at the base of
a mountain slope; esp., such a deposit of fine-grained texture (silt or
silty clay) deposited during time of flood. Syn:alluvial deposit;
alluvion. AGI
b. A driller's term for the broken, earthy rock material directly below
the soil layer and above the solid, unbroken bed or ledge rock. Etymol:
Latin alluvius, from alluere, to wash against. Plural: alluvia; alluviums.
AGI




almagra

Sp. A deep-red ocher originally from Andalusia, Spain, similar to Indian
red. Used as a pigment and in polishing glass and metals. Also spelled
almagre. Standard, 2




almandine

a. An isometric mineral, 8[Fe32+ Al2 Si3 O
12 ] ; pyralspilite subgroup of the garnet group, with Fe replaced
by Mg, Mn, and Ca; in red to brownish-black dodecahedral and trapezohedral
crystals, or massive; Mohs hardness, 7-1/2; occurs in medium-grade
metamorphic rock and felsic igneous rocks; used as a gemstone and an
abrasive. Formerly called almandite; alamandine; almond stone.
b. A violet or mauve variety of ruby spinel; a reddish-purple to
purplish-red spinel.
c. A reddish-purple sapphire (almandine sapphire).




almandine ruby

A violet-colored magnesium spinel. Syn:ruby spinel




almandite

Former spelling of almandine.




almeria ore

A Spanish hematite. Osborne




almond furnace

A furnace in which the slags of litharge left in refining silver are
reduced to lead by being heated with charcoal. Fay




almond stone

Former name for almandine.




alnoite

A lamprophyre chiefly composed of biotite or phlogopite and melilite as
essential minerals, commonly with olivine, calcite, and clinopyroxene.
Perovskite, apatite, nepheline, and garnet may be present. Its name
(Rosenbusch, 1887) is derived from Alnoe, Sweden. Also spelled allnoeite;
alnoeite. AGI




Aloxite

Trade name for fused crystalline alumina or artificial corundum used as an
quartz and beta quartz. Hess
b. Adj. Of or relating to one of two or more closely related minerals and
specifying a particular physical structure (esp. a polymorphous
modification); specif. said of a mineral that is stable at a temperature
lower than those of its beta and gamma polymorphs (e.g., "alpha
cristobalite" or "alpha -cristobalite," the low-temperature tetragonal
phase of cristobalite). Some mineralogists reverse this convention, using
alpha for the high-temperature phase (e.g., "alpha carnegieite," the
isometric phase of carnegieite stable above 690 degrees C). AGI
c. In crystallography the angle between the b and c axes.




alpha alumina

A white, anhydrous, nonhygroscopic powder, Al2 O3 , produced
when precipitated Al(OH), is calcined at 1,000 degrees C. It is the
natural product of the Bayer process and other processes used (or
proposed) to treat bauxite, clay, or other aluminum-bearing materials.
Newton, 1


alpha celsian

A silicate of aluminum and barium, BaAl2 Si2 O8 . An
artificial feldspar, similar to anorthite, but containing barium instead
of calcium. Hexagonal prisms. Uniaxial, negative. English




alpha chalcocite

See:digenite




alpha hyblite

A porcelain-white, hydrous acidic sulfosilicate of thorium with some
uranium, iron, and lead; isotropic. An alteration product of thorite. From
Hybla, ON, Can. English




alpha mercuric sulfide

See:vermilion




alpha quartz

A quartz polymorph stable below 573 degrees C; a common constituent of
crustal rocks. Syn:low quartz




alpha zinc sulfide

Colorless when pure; hexagonal; ZnS; mol wt., 97.43; sp gr, 3.98 to 4.1;
Mohs hardness, 3.5 to 4.0; luster, resinous; transformation temperature
from beta zinc sulfide to alpha zinc sulfide, 1,020+ or -5 degrees C:
sublimes at 1,180 degrees C or 1,185 degrees C; melting point, 1,850
degrees C (at 150 atm); insoluble in water and in acetic acid; and very
soluble in other acids. Occurs as the brownish-black mineral wurtzite,
which is unstable compared with its stable dimorph, the mineral sphalerite
(beta zinc sulfide), to which it inverts during alteration and from which
it is formed by heating sphalerite to the transformation temperature. Can
be crystallized from acid solutions above 250 degrees C.
See also:wurtzite; zinc sulfide. CF:beta zinc sulfide
Handbook of Chemistry and Physics, 2; Dana, 2




alpine

a. Pertaining to, characteristic of, or resembling the European Alps or
any lofty mountain or mountain system, esp. one modified by intense
glacial erosion. Spelled Alpine when referring specif. to European Alps.
AGI
b. Characteristic or descriptive of the mountainous regions lying between
timberline and snowline; said of the climate, flora, relief, ecology, etc.
Less strictly, pertaining to high elevations and cold climates.
AGI
c. A general term for topographical and structural features that resemble
in grandeur and complexity those of the European Alps, regardless of the
age or location of the mountains and features so described. AGI




Alpine diamond

See:pyrite




alquifou

A coarse-grained variety of galena used by potters in preparing a green
glaze.




alshedite

A variety of titanite containing yttria; found in Sweden.
Standard, 2




alstonite

A triclinic mineral, BaCa(CO3 )2 ; pseudo-orthorhombic and
trimorphous with barytocalcite and paralstonite. Formerly called bromlite.




altaite

An isometric mineral, PbTe ; in veins with gold, sulfides, and other
tellurides.




alteration

Any change in the mineralogic composition of a rock brought about by
physical or chemical means, esp. by the action of hydrothermal solutions;
also, a secondary, i.e., supergene, change in a rock or mineral.
Alteration is sometimes considered as a phase of metamorphism, but is
usually distinguished from it because of being milder and more localized
than metamorphism is generally thought to be. AGI




altered mineral

A mineral that has undergone chemical change by geologic (esp. weathering
or hydrothermal) processes.




altered rock

A rock that has undergone changes in its chemical and mineralogic
composition since its original formation. AGI




altered stone

a. Said of a stone that has undergone chemical and/or mineralogical
changes under geologic processes.
b. Any stone of which the appearance, esp. the color, has been changed by
any artificial means whatsoever. For example, heat is often used to
improve or alter color. Such change may be either external or internal.
See also:treated stone; stained stone.




alternate pillar and stope

See:square-set stoping




alternate polarity

Arrangement in magnetic separator whereby ore travels alternately through
normal concentration and entropy fields, thus stirring attracted material
and shaking out entrained nonmagnetics. Pryor, 1




alternating-current ampere

Current that will produce heat at the same rate as a direct-current
ampere, when flowing through a given ohmic resistance. Kentucky




alto

A term used in the southwestern United States for a bluff, height, or
hill. Etymol: Sp., high ground. AGI




alum

a. Any hydrous, alkali aluminum sulfate mineral, including kalinite,
potassium alum, sodium alum, mendozite, tschermigite, and lonecreekite.
Syn:potash alum
b. A former name for kalinite and potassium alum.
c. Any salts that are double sulfates of aluminum, chromium, iron, or
manganese and one of the alkali metals.


alum cake

A product of the action of sulfuric acid on clay, consisting chiefly of
silica and aluminum sulfate. Webster 3rd




alum earth

An argillaceous rock, commonly a shale, containing marcasite or pyrite
which, as it decomposes, forms sulfuric acid that attacks the shale and
produces alum. Many such rocks are carbonaceous. See also:alum shale
Hess




alumina

An oxide of aluminum, Al2 O3 ; the mineral corundum; an
important constituent of clay minerals, Al2 Si2 O5
(OH)4 , determining their suitability for firebrick and furnace
linings. Synthetic alumina is used as the feed material in aluminum
smelters; it is also used in the preparation of paints called lakes, in
dyeing, and in calico printing; in granular form it is used for abrasives
and grinding or cutting tools of high tensile strength. Most alumina is
made via the Bayer process from hydrated aluminum oxides, as found in
bauxite, diaspore, and gibbsite. Aluminum oxide can also be made in an
electric furnace by fusing bauxite or corundum. Suitably doped alumina is
the feed material for boules of synthetic ruby and sapphire made by the
Verneuil flame-fusion process. Fused alumina is crushed and used as an
abrasive, a refractory, a heating element for electrical heaters, and as a
filtering medium.




aluminate

A compound having the general formula, MAlO2 or M3 AlO (sub
3) , in which M indicates a monovalent metal. Mineral aluminates, such as
MgAl2 O4 , are termed spinels. Bennett




alumina trihydrate

A2 O3 .3H2 O or Al(OH)3 ; monoclinic; white;
crystalline powder, balls, or granules; sp gr, 2.42; obtained from bauxite
and used as a source of aluminum. CCD, 2; Lee




aluminite

A monoclinic mineral, Al2 (SO4 )(OH)4 .7H2 O ;
pseudo-orthorhombic, formerly called websterite. Syn:alley stone;
argil.




aluminosilicate refractory

A general term that includes all refractories of the fireclay,
sillimanite, mullite, diaspore, and bauxite types. Dodd




aluminous abrasive

An abrasive produced by fusing aluminum oxide. Mersereau, 2




aluminous ore

Ore in which the gangue consists principally of alumina. Osborne




aluminum

A light, silvery-white, ductile metal with high electrical conductivity
and good resistance to corrosion. Obtained from bauxite. Symbol, Al. It is
the lightest of the metals in general use commercially and is the basis
for light alloys used in the construction of modern aircraft and rockets;
aluminum coatings are used for telescope mirrors, decorative paper,
packages, and toys. The oxide, alumina, occurs naturally as ruby,
sapphire, corundum, and emery. Handbook of Chemistry and Physics, 3




aluminum detonator

See:Briska detonator.




aluminum silicates

Varying proportions of Al2 O3 and SiO2 . Occur
naturally in clays. Used in the glass and ceramics industry.
CCD, 2




alumite

See:alunite




alumocalcite

A variety of opal with alumina and lime as impurities. Fay




alumogel

An amorphous aluminum hydroxide that is a constituent of bauxite. Formerly
called cliachite, diasporogelite, and sporogelite.




alum rock

See:alunite




alum salt

Natural salt from which alum can be made. See also:halloysite;
kaolinite. Sanford




alum schist

See:alum shale




alum shale

An argillaceous, often carbonaceous, rock impregnated with alum,
originally containing iron sulfide (pyrite, marcasite) which, when
decomposed, formed sulfuric acid that reacted with the aluminous and
potassic materials of the rock to produce aluminum sulfates.
Syn:alum earth; alum schist; alum slate. AGI




alum slate

See:alum shale




alunite

a. A trigonal mineral, KAl3 (OH)6 (SO4 )2 ;
massive or disseminated; in pale tints; formed from sulfuric acid acting
on potassium feldspar in volcanic regions (alunization), and around
fumaroles. Formerly called alumstone, alum rock, alumite.
b. A mineral group including jarosite.


alunitization

Introduction of, or replacement by, alunite. AGI




alunogen

A triclinic mineral, Al2 (H2 O)12 (SO4 ) (sub
3) .5(H2 O) ; in fibrous masses or crusts; white, tinged yellow to
reddish, with sharp acid taste; in acid environments filling crevices in
coals, slates, gossans, and fumaroles. Syn:feather alum; hair salt.




alvanite

A monoclinic mineral, (Zn,Ni)Al4 (VO3 )2 (OH) (sub
12) .2H2 O ; forms light-blue-green rosettes in the vanadium
deposits of Karatau, Kazakhstan.




alveoli

The lungs can be thought of as two elastic bags containing millions of
little distensible air sacs. These air sacs or alveoli are all connected
to the air passages, which branch and rebranch like the twigs of a tree.
Hunt




alvite

A zirconium mineral; a source of hafnium, containing 16% HfO2 ;
tetragonal. Obtained from Alve, Norway. Kirk; Webster 2nd




amalgam

a. A naturally occurring alloy of silver with mercury; mercurian silver.
It is found in the oxidation zone of silver deposits and as scattered
grains in cinnabar ores. Syn:argental mercury
AGI
b. A general term for alloys of mercury with one or more of the well-known
metals (except iron and platinum); esp. an alloy of mercury with gold,
containing 40% to 60% gold, and obtained from the plates in a mill
treating gold ore. AGI




amalgamate

a. To unite (a metal) alloy with mercury. Standard, 2
b. To form an amalgam with; as, mercury amalgamates gold.
Standard, 2




amalgamated claims

Eng. Mining claims adjoining one another that have been grouped into one
claim for more economical working.




amalgamating barrel

A short, cylindrical vessel or barrel, with solid ends turned to fit
bearings, used for amalgamating battery accumulations and other material.
See also:amalgamator




amalgamating table

A sloping wooden table covered with a copper plate on which the mercury is
spread in order to amalgamate with the precious metal particles.
CTD




amalgamation

a. The production of an amalgam or alloy of mercury.
b. The process by which mercury is alloyed with some other metal to
produce an amalgam. It was used at one time for the extraction of gold and
silver from pulverized ores, but has been superseded by the cyanide
process. Barger




amalgamation process

A process of gold or silver recovery in which the ore, finely divided and
suspended in water, is passed over a surface of liquid mercury to form an
amalgam that is subjected to fire-refining processes for the recovery of
the gold or silver. Syn:amalgam treatment




amalgamator

An apparatus used in mining for bringing pulverized ore into close contact
with mercury to extract free metal from it by amalgamation.
See also:amalgamating barrel




amalgam barrel

A small, cylindrical batching mill used to grind auriferous concentrates
gently with mercury. Pryor, 3




amalgam pan

A muller mill with a horizontal rotating disk bearing on a fixed plate.
Gold-bearing material and mercury flow pulpwise between them.
Pryor, 3




amalgam plate

A sheet of metal with an adherent film of mercury that seizes gold from
flowing pulp. Pryor, 3




amalgam retort

The vessel where mercury is distilled from gold or silver amalgam.
Nelson




amalgam treatment

See:amalgamation process




amang

A term used in Malaysia for the heavy iron and tungsten minerals (and
associated minerals) found with placer cassiterite deposits. AGI




amarantite

A triclinic mineral, Fe(SO4 )(OH).3H2 O .




amargosite

The trade name for a bentonite from the Amargosa River, CA.
Syn:montmorillonite


amatrice

a. See:variscite
b. A green gem cut from variscite and its surrounding matrix of gray,
reddish, or brownish crystalline quartz or chalcedony.




amause

See:trass




amazonite

A bright, apple- or blue-green variety of microcline; may be carved for
art objects. Syn:amazonstone




amazonstone

See:amazonite




amber

a. A mineraloid; amorphous hydrocarbons from resins secreted by trees or
shrubs upon injury, derived by oxidation and polymerization of nonvolatile
terpenoids; in sedimentary rocks and on beaches, e.g., Baltic Sea.
See also:chemawinite
b. A hard, brittle fossil resin, yellow to brown, that takes a fine
polish; may contain fossil insects and plant matter. Syn:succinite;
bernstein; electrum. See also:resin
c. A group of fossil resins containing considerable succinic acid and
having highly variable C:H:O ratios; e.g., almashite, simetite,
delatynite, and ambrosine. See also:copal




Amberine

A local trade name for a yellowish-green variety of chalcedony from Death
Valley, CA. English




amberite

Former spelling of amber.




amber mica

See:phlogopite




amberoid

A gem material consisting of small fragments of genuine amber artificially
united or reconstructed by heat and pressure; may be characterized by an
obvious flow structure or a dull spot left by a drop of ether. Also
spelled ambroid. Syn:pressed amber




amber opal

A brownish-yellow variety of opal stained by iron oxide.




ambient

a. The environment surrounding a body but undisturbed or unaffected by it.
Hy
b. Encompassing on all sides; thus, ambient air is the air surrounding.
Strock, 2




ambrosine

A yellowish to clove-brown amber found in the phosphate beds near
Charleston, SC; it may be a modern resin that has been subjected to the
action of salt water. Rich in succinic acids. Fay; Tomkeieff




amenability

Characteristic reactions of minerals to basic methods of mineral
processing, studied in preliminary testwork on unknown ores.
Pryor, 3




American

Permissible explosive used in coal mines. Bennett




American-Belgian furnace

A direct-fired Belgian furnace used in the United States, conforming
essentially to the Liege design. Fay




American forge

See:Champlain forge




American jade

a. Nephrite in Wyoming.
b. See:californite




American ruby

A red pyrope garnet in Arizona and New Mexico.




American system

See:churn drill




American Table of Distances

The quantity-distance table, prepared and approved by the Institute of
Makers of Explosives (IME), for storage of explosive materials to
determine safe distances from inhabited buildings, public highways,
passenger railways, and other stored explosive materials.




amesite

An apple-green silicate mineral belonging to the phyllosilicate group and
occurring in foliated hexagonal plates. See also:magnesium kaolinite
Kirk; Webster 3rd


amethyst

a. A transparent to translucent, purple to pale-violet variety of quartz
common as a semiprecious gemstone. The color results from a hole defect
associated with ferric iron substitution for silicon.
Syn:bishop's stone
b. A term applied to a deep-purple variety of corundum and to a pale
reddish-violet variety of beryl.




amethystine

A color designation meaning violet to purplish, used as in amethystine
glass and amethystine sapphire.




amethystine quartz

A phenocrystalline variety of quartz colored purplish or bluish violet by
manganese. See also:lavendine




amethyst point

Amethyst crystal, from a geode, commonly possessing only the six (or
possibly three) rhombohedral terminal faces; generally with gradational
color, the best at the apex commonly grading to colorless at its base.




amianthinite

See:asbestos




amianthus

Syn:asbestos
Also spelled amiantus.




amiantoid

a. Having the appearance of asbestos. Standard, 2
b. An olive-green, coarse, fibrous variety of asbestos.
Standard, 2




amigo

A stick, tied to the end of a rope, on which workers sit when being raised
or lowered in shafts. Hess




aminoffite

A tetragonal mineral, Ca2 (Be,Al)Si2 O7 (OH).H (sub
2) O ; in colorless crystals in Sweden.




ammine

One of a group of complex compounds formed by coordination of ammonia
molecules with metal ions. McGraw-Hill, 1




ammiolite

A red or scarlet earthy substance, probably a mixture of copper antimonate
and cinnabar; said to occur in some Chilean ore deposits.




ammite

A 17th and 18th century term for a sedimentary rock now called oolite.
Obsolete syn: ammonite.




ammonal

An explosive used mainly for heavy quarry blasts in dry boreholes. It
consists of TNT, ammonium nitrate, and powdered aluminum. Nelson




ammonia

A colorless, gaseous alkaline compound; NH3 ; lighter than air;
pungent smell and taste. Byproduct of gas and coke production. Used in
making fertilizers and explosives.




ammonia dynamite

Dynamite in which part of the nitroglycerin is replaced by ammonium
nitrate; used in mining. See also:extra dynamite




ammonia gelatin

An explosive of the gelatin-dynamite class containing ammonium nitrate.
Webster 3rd




ammonia gelatin dynamite

See:gelatin dynamite




ammonia niter

Ammonium nitrate, NH4 NO3 ; nitrammite. Also spelled ammonia
nitre. Spencer, 4




ammonia stillman

In the coke products industry, one who extracts ammonia from liquor for
use in producing ammonium sulfate by circulating substances through stills
and auxiliary equipment. Also called pump-and-still operator; byproducts
stillman. DOT




ammoniojarosite

A trigonal mineral, (NH4 )Fe3 (SO4 )2 (OH)
6 ; alunite group. It occurs in pale yellow lumps of tabular grains
on the west side of the Kaibab fault, southern Utah.




ammonium chloride

NH4 Cl ; isometric; and colorless. When dissolved in water, it is
used as an electrolyte for some primary cells. Obtained as a byproduct in
gas manufacture. Used as a flux in soldering. Also called sal ammoniac.
Crispin


ammonium hydroxide

A solution of ammonia in water, NH4 OH . CTD




ammonium nitrate

Used in explosives and as a fertilizer. NH4 NO3 ; mol wt,
80.04; colorless. Bennett




ammonium nitrate gelignites

These explosives are similar to the straight gelatins except that the main
constituent is ammonium nitrate instead of sodium nitrate. Ammonium
nitrate is a more active explosive ingredient than sodium nitrate;
therefore it can be substituted for nitroglycerin in much larger
quantities and still give explosives of high weight strength. The
nitroglycerin content is usually 25% to 35%, and the ammonium nitrate
content ranges from about 30% to 60%. Ammonium nitrate gelignites are
characterized by plastic consistency; high densities of 1.5 to 1.6 g/cm
3 ; medium velocity of detonation of 2,500 m/s; and good fume
properties. The ammonium nitrate gelignites are useful all-purpose
explosives and are widely used in metal mines, nongassy coal mines,
quarries, tunneling, and construction work. Its wide range of strengths
enables a suitable grade to be selected for blasting almost every variety
of rock from hard to soft. McAdam, 2




amoibite

A former named for gersdorffite.




amorphous

a. Said of a mineral or other substance that lacks crystalline structure,
or whose internal arrangement is so irregular that there is no
characteristic external form. Ant. crystalline. AGI
b. The state of a solid lacking crystal structure, specif. lacking
long-range order.
c. A term formerly used to describe a body of rock occurring in a
continuous mass, without division into parts. CF:massive




amorphous coal

A somewhat inaccurate term for a coal in which distinct plant material is
not discernible. Tomkeieff




amorphous graphite

Very fine-grained, generally sooty graphite from metamorphosed coalbeds.
The word amorphous is a misnomer because all graphite is crystalline. The
term has also been applied to very fine particles of flake graphite that
can be sold only for low-value uses (such as foundry facings), and to
fine-grained varieties of Ceylon lump graphite. AGI




amorphous metal

Metal in which the regular arrangement of atoms characteristic of the
crystalline state has been destroyed. CTD




amorphous mineral

A mineral with no definite crystalline structure. Nelson




amorphous peat

A type of peat in which the original structure of the plants has been
destroyed as the result of decomposition of the cellulose matter. It is
heavy, compact, and plastic when wet. See also:fibrous peat
Tomkeieff




amorphous phosphorus

See:phosphorus




amosite

a. A monoclinic mineral in the cummingtonite-grunerite series.
Sinclair, 7
b. A commercial asbestos composed of asbestiform gedrite, grunerite, or
anthophyllite of the amphibole group; has typically long fibers.




ampangabeite

A former name for samarskite.




ampelite

An obsolete term for a black carbonaceous or bituminous shale. AGI




ampelitis

An ancient name applied to a variety of bituminous earth used as an
insecticide sprinkled over vines. Tomkeieff




ampere

The practical unit of electric current. The current produced by 1 V acting
through a resistance of 1 Omega . Webster 3rd




ampere-hour

The quantity of electricity carried past any point of a circuit in 1 h by
a steady current of 1 A; 1 A.h equals 3,600 C. Webster 3rd




ampere volt

A watt. Standard, 2




amphibole

A mineral group; characterized by double chains of silica tetrahedra
having the composition A0-1 B2 Y5 Z8 O (sub
22) (OH,F,Cl) , where (A=Ca,Na,K,Pb,B), (B=Ca,Fe,Li,Mg,Mn,Na),
(Y=Al,Cr,Fe,Mg,Mn,Ti), and (Z=Al,Be,Si,Ti); in the orthorhombic or
monoclinic crystal systems, including actinolite, anthophyllite,
arfvedsonite, cummingtonite, hornblende, richterite, glaucophane,
grunerite, anthophyllite, riebeckite, tremolite, and others. All display a
diagnostic prismatic cleavage in two directions parallel to crystal faces
and intersecting at angles of about 54 degrees and 124 degrees . Some
members may be asbestiform. See also:pyroxene




amphibole-magnetite rock

A granular, more or less banded rock containing grunerite, other
ferruginous silicates, and magnetite; produced by metamorphism of
ferruginous cherts, such as taconite and jaspillite.




amphibolide

A general term, for use in the field, to designate any coarse-grained,
holocrystalline igneous rock almost entirely composed of amphibole
minerals. Syn:amphibololite


amphibolite

A crystalloblastic rock consisting mainly of amphibole and plagioclase
with little or no quartz. As the content of quartz increases, the rock
grades into hornblende plagioclase gneiss. CF:feather amphibolite
AGI




amphibolite facies

The set of metamorphic mineral assemblages (facies) in which basic rocks
are represented by hornblende + plagioclase, the plagioclase being
oligoclase-andesine or some more calcic variety. Epidote and almandine are
common in amphibolites. The facies is typical of regional dynamothermal
metamorphism under moderate to high pressures (in excess of 300 MPa) with
temperatures in the range 450 to 700 degrees C. AGI




amphibololite

See:amphibolide




amphigene

See:leucite




amphoteric

Having both acidic and basic properties. CTD




amygdale

See:amygdule




amygdaloid

An extrusive or intrusive rock containing numerous amygdules. Said of a
rock having numerous amygdules. Syn:amygdaloidal; mandelstone.
See also:amygdule




amygdaloidal

a. Said of rocks containing amygdules and of the structure of such rocks;
e.g., certain basaltic lava sheets on Keweenaw Point, Lake Superior, which
have amygdules filled with native copper, and are important sources of the
metal. Syn:amygdaloid; amygdule. AGI
b. Almond-shaped. Zern




amygdaloidal rock

A rock containing amygdules, or the structure of a rock resulting from its
presence. Schieferdecker




amygdule

A gas cavity or vesicle, in an igneous rock, that is filled with such
secondary minerals as calcite, quartz, chalcedony, or a zeolite. The term
amygdale is preferred in British usage. Syn:amygdaloidal
See also:amygdaloid




amyl alcohol

C5 H11 OH ; a frothing agent. Pryor, 3




amyl xanthate

A powerful collector agent used in the flotation process. Pryor, 1




Anaconda method

A bunch-blasting method in which 6 to 15 fuses, cut to respective lengths
2 in (5.1 cm) longer than required, are tied together near one end by two
ravelings of fuse spaced about 5 to 6 in (12.7 to 15.2 cm) apart. A
special cutter cuts the fuses off evenly between the two ties, leaving the
fuses tied together and offering a smooth face of cut ends. Another bunch
is made from the fuses of the remaining holes in the round. By using a
short notched fuse as a spitter, the flame is directed against the cut end
of one bunch of fuses. As soon as this bunch ignites, it is held close to
the face of the second bunch, moving slowly to contact all fuses with the
flame from the first bunch. Bunches should be held at least 6 in back from
the end to avoid burning the hands. By this method, all the holes of a
round are fired in only two groups and by one spitter. Lewis




anaerobic

a. Said of an organism (esp. a bacterium) that can live in the absence of
free oxygen; also, said of its activities.--n. anaerobe. AGI
b. Said of conditions that exist only in the absence of free oxygen.
CF:aerobic




analcime

An isometric mineral, 16[Na(H2 O)(AlSi2 O6 )] ;
zeolite group; in white to slightly tinted radiating aggregates or
granular masses; a late primary or hydrothermal mineral in mafic igneous
rocks, an alkaline lake precipitate, and in silicic tuffs and tuffaceous
sandstones. Formerly called analcite.




analcimite

An extrusive or hypabyssal igneous rock consisting mainly of analcime and
pyroxene (usually titanaugite). Feldspathoids, plagioclase, and/or olivine
may be present. Apatite, sphene, and opaque oxides may be present as
accessories. AGI




analcimization

Replacement of feldspars or feldspathoids by analcime, usually in igneous
rocks during late magmatic or postmagmatic stages. Syn:analcitization
AGI




analcitization

See:analcimization




analog computer

A computer that operates with numbers represented by directly measurable
quantities (such as length, voltage, or resistance) in a one-to-one
correspondence; a measuring device that operates on continuous variables
represented by physical or mathematical analogies between the computer
variables and the variables of a given problem to be solved. AGI




analogous

a. Corresponding to or resembling something else in some way, as in form,
proportion, etc.
b. Designating that pole (end) of a pyroelectric crystal to which heating
gives a positive charge. CF:antilogous




analytical chemistry

Study of the qualitative or quantitative composition of materials.
Pryor, 3


analytic group

A rock-statigraphic unit formerly classed as a formation but now called a
group because subdivisions of the unit are considered to be formations.




analyzer

The part of a polariscope that receives the light after polarization and
exhibits its properties. In a petrographic microscope, it is the
polarizing mechanism (Nicol prism, Polaroid, etc.) that intersects the
light after it has passed through the object under study.
See also:polarizer




anamigmatization

High-temperature, high-pressure remelting of preexisting rock to form
migma. CF:anatexis




anamorphic zone

The zone deep in the Earth's crust in which rock flowage takes place. The
term, originated in 1898 by Van Hise, is now little used.
CF:anamorphism




anamorphism

Intense metamorphism in the anamorphic zone in which rock flowage takes
place and simple minerals of low density are changed into more complex
ones of greater density by silication, decarbonization, dehydration, and
deoxidation. The term was originated by Van Hise in 1904.
CF:anamorphic zone; katamorphism. AGI




anastomosing

a. Pertaining to a network of branching and rejoining fault or vein
surfaces or surface traces. AGI
b. Said of the channel pattern of a braided stream. AGI




anatase

A tetragonal mineral, 4[TiO2 ] ; trimorphous with rutile and
brookite; brown, greenish-gray, or black; in hydrothermal veins around
granite pegmatites, as an alteration of titanium minerals, and as detrital
grains. Formerly called octahedrite. See also:octahedrite;
titanium dioxide; xanthitane.




anatectic

See:anatexis




anatexis

Melting of preexisting rock. This term is commonly modified by terms such
as intergranular, partial, differential, selective, or complete. Adj.
anatectic. CF:palingenesis; syntexis; anamigmatization. AGI




anauxite

A clay mineral near kaolinite, but containing excess silica, probably as
interlayered sheets. Monoclinic. AGI; Dana, 4




Anbauhobel

A rapid plow for use on longwall faces. It is suitable for seams from 2 to
8 ft (0.6 to 3.9 m) thick, with reasonably good roof and floor. The plow
travels along the face at a speed of 75 ft/min (22.9 m/min) with a cutting
depth from 1-1/2 to 3 in (3.8 to 7.6 cm); the broken coal is loaded by the
plow-shaped body onto an armored conveyor. The machine can be operated
independently of the face conveyor. See also:plow-type machine;
Rehisshakenhobel. Nelson




anchaduar

Fillings of old workings in a mine, and said to carry gold of recent
deposition. This is a product that deposits in most of the old stopes
throughout the mine. In some instances, the whole stope for 20 ft (6.1 m)
wide is filled. It is apparently siliceous material with more or less
pyrite. Hess




anchorage

That portion of any beam or structure designed to resist pulling out or
slipping of the beam or structure when subjected to stress. Nelson




anchor bolt

a. A bolt with the threaded portion projecting from a structure, generally
used to hold the frame of a building secure against wind load or a machine
against the forces of vibration. Also called holding-down bolt; foundation
bolt. Hammond
b. A bolt or other device used to secure a diamond-drill base to a solid
foundation. It may or may not be threaded. Long
c. A lag screw used to anchor the drill base to a platform or sill.
Long




anchor charge

Means of fastening an explosive charge in a seismic shot hole to allow
several charges to be preloaded. At each stage the bottom charges are
fired first, the upper charges being held down by anchors. AGI




anchor jack

See:jack




anchor prop

See:stell prop




ancylite

A mineral, SrCe(CO3 )2 (OH).H2 O ; in pegmatites.




andalusite

An orthorhombic mineral, Al2 SiO5 ; trimorphous with kyanite
and sillimanite; Mohs hardness, 7-1/2; in aluminous shales and slates
subjected to high-temperature, low-stress metamorphism; transparent green
varieties used as gems. Syn:cross-stone




andersonite

A trigonal mineral, Na2 Ca(UO2 )(CO3 )3 .6H
2 O ; bright yellow-green; secondary.




Anderton shearer loader

A widely used cutter loader in which the ordinary jib of the longwall coal
cutter is replaced by a shear drum which cuts a web from 16 to 22 in (40.6
to 55.9 cm) depending on its width. The machine travels on an armored
conveyor and requires a prop-free front for working. It shears the coal in
one direction and the front coal is loaded by a plow deflector, and then
returns along the face (without cutting) and loads the remainder of the
broken coal. The ordinary Anderton is suitable for coal seams more than 3
ft 6 in (1.1 m) thick. Nelson


andesine

A triclinic mineral, (Na,Ca)[(Si,Al)AlSi2 O8 ] , NaSi 50 to
70 mol %, CaAl 50 to 30 mol %; of the plagioclase series of the feldspar
group with prismatic cleavage; white to gray; a common rock-forming
mineral in andesites, differentiated gabbros, some anorthosites, and as
detrital grains.




andesinite

A coarse-grained igneous rock almost entirely composed of andesine. It was
named by Turner in 1900. CF:anorthosite
AGI




andesite

A dark-colored, fine-grained extrusive rock that, when porphyritic,
contains phenocrysts composed primarily of zoned sodic plagioclase (esp.
andesine) and one or more of the mafic minerals (e.g., biotite,
hornblende, pyroxene), with a groundmass composed generally of the same
minerals as the phenocrysts, although the plagioclase may be more sodic,
and quartz is generally present; the extrusive equivalent of diorite.
Andesite grades into latite with increasing alkali feldspar content, and
into dacite with more alkali feldspar and quartz. It was named by Buch in
1826 from the Andes Mountains, South America. AGI




andorite

An orthorhombic mineral, PbAgSb3 S6 . Syn:sundtite




andradite

An isometric mineral, 8[Ca3 Fe2 Si3 O12 ] ;
never pure; garnet group; in yellow, green, red, brown, or black
dodecahedral and trapezohedral crystals, or may be massive; in calcareous
metasediments and placers. Varieties include topazolite, demantoid,
melanite, aplome, and bredbergite.




andre

A direction of coal face roughly halfway between the main (bord) and
secondary (end) cleavages; on the cross. Mason




Andreasen pipette

An instrument used in the determination of the particle size of clays by
the sedimentation method. Dodd




Andrews' elutriator

A device for particle size analysis. It consists of (1) a feed vessel or
tube, (2) a large hydraulic classifier, (3) an intermediate classifier,
and (4) a graduated measuring vessel. Dodd




andrewsite

An orthorhombic mineral, (Cu,Fe)Fe3 (PO4 )3 (OH) (sub
2) ; in bluish-green globules with radial structure.




anemoclastic

Broken off by wind erosion and rounded by wind action.




anemogram

A continuous record of wind speed and direction given by an anemograph.
Hammond




anemograph

A self-recording anemometer giving a continuous trace of the direction and
velocity of surface wind. In the Dines tube anemograph, the wind pressure
acts upon the opening of a tube arranged as a vane to face in the
direction of the wind. Pressure is transmitted through the tube to a float
carrying a pen, the height of which indicates the wind velocity.
Hammond




anemolite

a. An upturned form of calcite stalactite; its form is supposed to have
been caused by air currents. English
b. A stalactite with one or more changes in its growth axis.
Syn:helictite




anemometer

An instrument for measuring air velocity. It consists of a small fan from
3 to 6 in (7.6 to 15.2 cm) in diameter that is rotated by the air current.
By simple gearing, the number of revolutions of the fan is recorded on
dials. It is held in the mine airway for the exact number of minutes (N),
the instrument being moved steadily over the entire area. The difference
between the initial and the final readings on the dials, divided by N,
gives the velocity of the air in feet per minute. Instruments are
available for velocities from near zero to 6,000 ft/min (1.83 km/min),
also with extension and remote control handles.
See also:vane anemometer; self-timing anemometer. Nelson




aneroid barograph

Consists essentially of an aneroid barometer and a revolving drum. The
movement of the evacuated spring can is transmitted and magnified through
a system of levers so that it is finally traced by means of a stylo on the
graph paper attached to the revolving drum. The drum is rotated by
clockwork, and can be of either the 24-h or the 7-day type. The graph
paper is usually marked off in hourly intervals, so that a complete record
of the atmospheric pressure at any instant may be obtained. These
barographs are used extensively in mining and in meteorological offices.
Morris




aneroid barometer

An instrument for measuring atmospheric pressure, built first by Lucien
Vidie in about 1843. Basically, variation in pressure with changes in
altitude is determined by the movements of the elastic top of a metallic
box from which the air has been partly exhausted. Used generally in
measuring altitude. AGI




ANFO

a. An explosive material consisting of ammonium nitrate and fuel oil.
b. A blasting product, with approx. 94.5% industrial-grade ammonium
nitrate and 5.5% No. 2 grade diesel fuel oil for a nearly oxygen-balanced
mix; available in bulk form for onsite mixing of the AN and fuel or in
50-lb (23-kg) premixed bags as pourable forms. A heavy ANFO product is
comprised of up to 45% to 50% ammonium nitrate emulsion mixed with prilled
ANFO to increase the bulk density of ANFO; it has improved strength and
provides good water resistance in comparison to ANFO. SME, 1




angelellite

A triclinic mineral, Fe4 (AsO4 )2 O3 ;
brownish-black, encrusted on andesite in northwestern Argentina.




angle beam

A two-limbed beam used for turning angles in shafts, etc. Zern




angle brace

A brace used to prevent mine timbers from riding or leaning; a brace
across an interior angle. Fay




angle-cut

Drill holes converge, so that a core is blasted out. This leaves an open
or relieved cavity or free face for the following shots, which are timed
to ensue with a fractional delay. Pryor, 3


angledozer

a. A bulldozer whose blade can be turned at an angle to the direction of
travel. Carson, 1
b. A power-operated machine fitted with a blade, adjustable in height and
angle, used for digging and side casting, and for spreading loose
excavated material; used at opencast pits and dumping sites.
Nelson
c. A bulldozer with a blade that can be pivoted on a vertical center pin,
so as to cast its load to either side. Syn:angling dozer
Nichols, 1




angle drilling

See:inclined drilling; inclined borehole.




angle hole

A borehole that is drilled at an angle not perpendicular to the Earth's
surface. Syn:incline hole




angle level

See:alidade




angle of attack

In mine fan terminology, the angle made by the direction of air approach
and the chord of the aerofoil section. Roberts, 1




angle of bite

In rolling metals where all the force is transmitted through the rolls,
maximum attainable angle between roll radius at the first contact and the
roll centers. If the operating angle is less, it is called the contact
angle or roll angle. ASM, 1




angle of dip

The angle at which strata or mineral deposits are inclined to the
horizontal plane. In most localities, earth movements subsequent to the
deposition of the strata have caused them to be inclined or tilted.
Syn:dip




angle of draw

a. In coal mine subsidence, this angle is assumed to bisect the angle
between the vertical and the angle of repose of the material and is 20
degrees for flat seams. For dipping seams, the angle of break increases,
being 35.8 degrees from the vertical for a 40 degrees dip. The main break
occurs over the seam at an angle from the vertical equal to half the dip.
Lewis
b. The angle between the limit line and the vertical. CF:draw
Nelson




angle of external friction

The angle between the abscissa and the tangent of the curve representing
the relationship of shearing resistance to normal stress acting between
soil and the surface of another material. ASCE




angle of extinction

In polarized-light microscopy, the angle between an extinction direction
and a crystallographic direction--e.g., crystal face, cleavage plane--of
an anisotropic mineral. An extinction angle of 0 degrees is called
"parallel extinction," an angle of 45 degrees "symmetrical extinction,"
other angles "oblique extinction;" of diagnostic value in mineral
identification. Syn:extinction angle




angle of friction

The angle between the perpendicular to a surface and the resultant force
acting on a body resting on the surface, at which the body begins to
slide. Hammond




angle of inclination

The angle of slope from the horizontal.




angle of nip

In a rock-crushing machine, the maximum angle subtended by its approaching
jaws or roll surfaces at which a piece of ore of specified size can be
gripped. See also:nip




angle of obliquity

The angle between the direction of the resultant stress or force acting on
a given plane and the normal to that plane. ASCE




angle of polarization

a. That angle, the tangent of which is the index of refraction of a
reflecting substance. Fay
b. The angle of reflection from a plane surface at which light is
polarized. Hess




angle of pull

The angle between the vertical and an inclined plane bounding the area
affected by the subsidence beyond the vertical. Applied to slides of
earth. Fay




angle of reflection

a. The angle that a reflected ray of light, on leaving the exterior or
interior surface of an object, such as a transparent stone or crystal,
makes with the normal to that surface.
b. An erroneous term for the Bragg angle of X-ray diffraction.




angle of repose

See:angle of rest




angle of rest

The maximum slope at which a heap of any loose or fragmented solid
material will stand without sliding or come to rest when poured or dumped
in a pile or on a slope. Syn:angle of repose
See also:natural slope




angle of shear

The angle between the planes of maximum shear, which is bisected by the
axis of greatest compression. Rice, 1




angle of slide

The slope, measured in degrees of deviation from the horizontal, on which
loose or fragmented solid materials will start to slide; it is a slightly
greater angle than the angle of rest.


angle of swing

The number of degrees through which the dipper or shovel bucket moves
horizontally from the filled position to the dumping position.
Carson, 1




anglesite

An orthorhombic mineral, 4[PbSO4 ] ; sp gr, 6.2 to 6.4; in the
supergene parts of lead-ore veins; a minor ore of lead. Formerly called
lead vitriol, lead spar.




angle to the right

Horizontal angle measured clockwise from the preceding line to the
following one. Seelye, 2




angle trough

A short curved section of a shaker conveyor trough inserted in a trough
line to change the angle of direction. Up to 15 degrees of turn, the angle
trough does not employ any means of support other than connection to
adjacent troughs. For a greater degree of turn, a fulcrum jack and a
swivel device are employed with the trough section. Jones, 1




angling

Rope will only coil closely on the drum within the distance between the
centers of the pulleys. Spread or diagonal coiling will result outside
this distance unless the drum is grooved: this is known as outside angling
and with a grooved drum may amount to 1?degrees . After the normal line
between the pulley and the drum is passed, the coils attempt to get back
to this normal line. This produces friction crushing between the coils and
a danger of coils mounting one over the other; this is known as inside
angling and should be kept below 2 degrees . The amount of angling for a
given distance between the pulleys will depend upon the distance between
the headgear pulleys and the drum. Grooving the drum reduces the
difficulties associated with angling. Syn:outside angling
Sinclair, 5




angling dozer

See:angledozer




angstrom

a. A unit of linear measurement in the centimeter-gram-second system. It
equals 10-10 m, 10-8 cm, 10-4 mu m, or 10
-1 nm. Such ultramicroscopic distances as the dimensions of atoms,
molecules, unit cells, and short wavelengths are expressed in angstroms.
Webster 2nd; Webster 3rd
b. Either of two units of wavelength: (1) 10-10 m, called the
absolute angstrom; or (2) the wavelength of the red spectrum line of
cadmium divided by 6,438.4696, which is called the international angstrom.
Webster 3rd




angular

Having sharp angles or borders; specif. said of a sedimentary particle
showing very little or no evidence of abrasion. AGI




angular cutter

A milling cutter on which the cutting face is at an angle with regard to
the axis of the cutter. Crispin




angularity test

See:slope test




angular unconformity

An unconformity in which the older underlying strata dip at a different
angle (generally steeper) than the younger overlying strata.
See also:disconformity




anhedral

Said of those minerals of igneous rocks that are not bounded by their own
crystal faces, but have an imperfect form impressed on them by the
adjacent minerals during crystallization. CF:euhedral; subhedral.
Syn:allotriomorphic; xenomorphic.




anhydride

a. A compound formed from an acid by removal of water.
McGraw-Hill, 1
b. An oxide of a nonmetallic element or an organic radical, capable of
forming an acid by uniting with the elements of water, or of being formed
by the abstraction of the water, or of uniting with basic oxides to form
salts.




anhydrite

An orthorhombic mineral, CaSO4 ; massive; primarily in evaporite
deposits, hot sulfate volcanic waters, and veins; hydrates to gypsum.
Formerly called cube spar.




anhydrock

A sedimentary rock composed chiefly of anhydrite. AGI




anhydrous

Said of a substance, e.g., magma or a mineral, that is completely or
essentially without water. An anhydrous mineral contains no water in
chemical combination. AGI




anhydrous ammonia

Purified ammonia gas, NH3 , liquefied by cold and pressure.




anidiomorphic

See:xenomorphic




aniline point

An approximate measure of the aromatic content of a mixture of
hydrocarbons. It is defined as the lowest temperature at which an oil is
completely miscible with an equal volume of aniline. Francis, 2




anilite

An orthorhombic mineral, Cu7 S4 ; alters to a digenitelike
crystal solution upon grinding.




animikite

A silver ore consisting of a mixture of sulfides, arsenides, and
antimonides, with striking intergrowths and in granular masses; contains
nickel and lead. CF:macfarlanite


anion

a. A negatively charged ion, such as a hydroxide, chloride, or sulfate
ion; opposite of cation. Webster 3rd
b. An atomic particle with a negative charge; one attracted to the anode.
CF:cation




anion exchange capacity

A measure of the ability of a clay to adsorb or exchange anions; usually
expressed in milliequivalents or anions per 100 g of dry clay.
ACSG, 2




anionic collector

A flotation reagent in which the reactive group is acid in character. In
these collectors the hydrocarbon group is in the anion. The most common
anionic collectors are fatty acids (carboxylic acids). They occur
naturally as complex mixtures in which the hydrocarbon chain is saturated
or unsaturated. Fuerstenau




anionic current

Negative-ion electrical current.




anionic detergent

A detergent in which the anion (negative ion) is the active part.
ASM, 1




anionic flotation

A flotation process employing anionic collectors. Anionic collectors are
those in which the negative ion (anion) is the effective part. Opposite of
cationic flotation, which employs cationic, or positive, ion collectors.




anisodesmic

a. An obsolete syn. for heterogranular.
b. Said of crystals with unequal dimensions, including those with
significant flattening, elongation, or both. Ant. isometric. CF:equant;
tabular.
c. See:heterogranular
d. Said of crystal structures with chemical bond strengths that are
directionally unequal; e.g., micas.




anisometric

a. Having unsymmetrical parts; not isometric; applied to crystals with
three unequal axes. Webster 3rd
b. Of or relating to a rock of granular texture but having mineral
constituents of unequal size. Webster 3rd
c. A textural term applied to granular rocks in which the grains are of
different sizes. Obsolete. The term "seriate" expresses the same texture
when the crystals vary gradually or in a continuous series.
CF:isodiametric; isometric. Johannsen




anisotropic

Having physical properties that vary in different directions. Specif. in
optical crystallography showing double refraction. Characteristic of all
crystalline substances, including minerals, except those belonging in the
isometric system, which are isotropic. Opposite of isotropic.
Fay; AGI




anisotropic fabric

A fabric in which there is preferred orientation of the minerals of which
the rock is composed.




anisotropy

a. The property of being anisotropic, or exhibiting properties (such as
velocity of light transmission, conductivity of heat or electricity, or
compressibility) with different values when measured along axes in
different directions. Webster 3rd
b. The condition of having different properties in different directions as
in geologic strata that transmit sound waves with different velocities in
the vertical and in the horizontal directions. AGI
c. Optically descriptive of crystalline materials having light velocities
and indices of refraction dependent upon the crystallographic direction of
the electric vector (vibration direction) during transmission or
reflection; it includes all nonisometric crystals. CF:uniaxial;
extinction; isotropy.
d. In geostatistics, the situation where a variogram exhibits a longer
range (i.e., better correlation) in one direction than in another.




ankerite

A trigonal mineral, Ca(Fe,Mg,Mn)(CO3 )2 ; dolomite group;
forms series with dolomite and with kutnohorite; associated with iron
ores; commonly forms thin veins in some coal seams. CF:ferroan dolomite;
cleat spar. See also:pearl spar




annabergite

A monoclinic mineral, 2[Ni3 (AsO4 )2 .8H2 O] ;
vivianite group with cobalt replacing nickel toward erythrite; occurs as
light-green soft coatings of fine striated crystals, or earthy; an
oxidation product of nickel and cobalt arsenides, the green crusts being a
distinctive guide to nickel ores. Formerly called nickel ocher.
CF:nickel bloom




annealed wire rope

A wire rope made from wires that have been softened by annealing.
Zern




annealing

a. Heating to and holding at a suitable temperature and then cooling at a
suitable rate for such purposes as reducing hardness; improving
machinability; facilitating cold working; producing a desired
microstructure; or obtaining desired mechanical, physical, or other
properties. When applied to ferrous alloys, the term "annealing", without
qualification, implies full annealing. When applied to nonferrous alloys,
annealing implies a heat treatment designed to soften a cold-worked
structure by recrystallization or subsequent grain growth or to soften an
age-hardened alloy by causing a nearly complete precipitation of the
second phase in relatively coarse form. ASM, 1
b. The variation of the cooling rate at different temperatures of
porcelain, glass, and other ceramic ware containing large quantities of
vitreous material to prevent defects such as dunting, crazing, cracking,
crystallization, etc.
c. The process by which glass and certain metals are heated and then
slowly cooled to make them more tenacious and less brittle. Important in
connection with the manufacture of steel castings, forgings, etc.
Fay
d. The process of heating metal shapes to a red heat or above, prior to
cleaning.




annealing color

The hue taken by steel in annealing. Standard, 2




annealing oven

A oven for heating and gradually cooling metals or glass to render them
less brittle. Also called annealing furnace. Standard, 2; Fay




annerodite

A black mixture of samarskite with parallel overgrowths of columbite. Also
spelled aanerodite.




annite

A monoclinic mineral, KFe3 AlSi3 O10 (OH,F)2 ;
mica group; trioctahedral.




annivite

A variety of tennantite with arsenic partly replaced by bismuth and
antimony.




annual labor

Same as assessment work, on mining claims.


annual layer

a. A sedimentary layer deposited or presumed to have been deposited during
the course of a year; e.g., a glacial varve. AGI
b. A dark band (in a salt stock) of formerly disseminated anhydrite
crystals that accumulated upon being freed by solution of the enclosing
salt. AGI




annual value

The annual value of a property is the estimated annual surplus of revenue
over expenditure in process of liquidating the mineral reserves. In the
usual case, that of a property owned by a company, it is the dividend
estimated maintainable annually over the whole computed life, the regular
distribution of mining profit. Truscott




annular bearing

A ring bearing that carries the radial load of a shaft. If a ball bearing,
the balls are held in a race and run on a hard band around the shaft.
Petroleum Age




annular-drainage pattern

A drainage pattern in which streams follow a roughly circular or
concentric path along a belt of weak rock, resembling in plan a ringlike
pattern. It is best displayed by streams draining a maturely dissected
structural dome or basin where erosion has exposed rimming sedimentary
strata of greatly varying degrees of hardness, as in the Red Valley, which
nearly encircles the domal structure of the Black Hills, SD. AGI




annular kiln

A kiln having compartments. Standard, 2




anode

a. The positive pole of an electrolytic cell. Webster 3rd
b. The terminal at which current enters a primary cell or storage battery;
it is positive with respect to the device and negative with respect to the
external circuit. McGraw-Hill, 1
c. The electropositive pole. AGI
d. The electrode at which electrons leave a device to enter the external
circuit; opposite of cathode. See also:electrode
e. The negative terminal of a primary cell or of a storage battery that is
delivering current. Webster 3rd




anode compartment

In an electrolytic cell, the enclosure formed by a diaphragm around the
anodes. ASM, 1




anode copper

Specially shaped copper slabs used as anodes in electrolytic refinement,
and resulting from the refinement of blister copper in a reverberatory
furnace. ASM, 1




anode effect

The effect produced by polarization of an anode in the electrolysis of
fused salts. It is characterized by a sudden increase in voltage and a
corresponding decrease in amperage due to the anode being virtually
separated from the electrolyte by a gas film. ASM, 1




anode furnace

A copper- or nickel-refining furnace, in which blister copper or impure
nickel is refined.




anode metals

Metals used for electroplating. They are as pure as commercially possible,
uniform in texture and composition, and have the skin removed by
machining. In addition to pure single metals, various alloys are produced
in anode form, such as Platers' brass and Spekwite, the latter yielding a
white plate harder than nickel. Brady, 2




anode mud

A deposit of insoluble residue formed from the dissolution of the anode in
commercial electrolysis. Sometimes called anode slime. In copper refining,
this slime contains the precious metals that are recovered from it.
ASM, 1; CTD




anode scrap

Remnants of anode copper retrieved from electrolytic refining of the
metal. Pryor, 3




anode slime

Metals or metal compounds left at, or falling from, the anode during
electrolytic refining. The plural form is often used.




anodic zone

In the electrical self-potential method of geophysical prospecting, if the
chemical composition of the soil or subsoil is such as to give electrical
polarization, the zone of electropositive potential is the anodic zone.
AGI




anomaly

a. A departure from the expected or normal. AGI
b. The difference between an observed value and the corresponding computed
value. AGI
c. A geological feature, esp. in the subsurface, distinguished by
geological, geophysical, or geochemical means, which is different from the
general surroundings and is often of potential economic value; e.g., a
magnetic anomaly. AGI
d. Any deviation from conformity or regularity. A distinctive local
feature in a geophysical, geological, or geochemical survey over a larger
area. An area or a restricted portion of a geophysical survey, such as a
magnetic survey or a gravity survey, that differs from the rest of the
survey in general. The anomaly might be associated with petroleum, natural
gas, or mineral deposits, or provide a key to interpreting the underlying
geologic structure. Drilling for economic mineral deposits might be
conducted in the area of a geophysical anomaly. In seismic usage, anomaly
is generally synonymous with subsurface structure or material properties,
but it is also used for spurious or unexplainable seismic events or for
local deviations of observed signals which cannot be conclusively
attributed to a unique cause. See also:hydrochemical anomaly
AGI
e. A gravity anomaly is the difference between the theoretical calculated
gravity and the observed terrestrial gravity. In comparing any set of
observed data with a computed theoretical curve, the difference of an
observed value and the corresponding computed value, or the observed minus
the computed value. Excess observed gravity is a positive anomaly, and a
deficiency is a negative anomaly. See also:Bouguer anomaly;
free-air anomaly; isostatic anomaly. AGI
f. A crystallographic anomaly is the lack of agreement between the
apparent external symmetry of a crystal and the observed optical
properties. Schieferdecker
g. Any departure from the normal magnetic field of the Earth is a magnetic
anomaly. It may be a high or a low, subcircular, ridgelike or valleylike,
or linear and dikelike. AGI




anorthic

Obsolete syn. for a triclinic crystal system. See also:triclinic




anorthite

a. A triclinic mineral, 4[CaAl2 Si2 O8 ] ;
plagioclase series of the feldspar group, with up to 10 mol % NaSi
replacing CaAl; white to gray; in ultramafic intrusive igneous bodies and
skarns. Syn:calcium feldspar; calcium plagioclase; calciclase;
lepolite.
b. A pure calcium end member of the plagioclase series.




anorthoclase

A triclinic mineral, 4[(Na,K)AlSi3 O8 ] ; feldspar group;
occurs in tabular crystals with prismatic cleavage; colorless or white; in
felsic volcanic rocks. CF:orthoclase




anorthosite

A plutonic rock composed almost entirely of plagioclase, usually
labradorite. It is a monomineralic equivalent of gabbro but lacks
monoclinic pyroxene. CF:andesinite




anorthositization

Introduction of, or replacement by, anorthosite. AGI


anoxia

Oxygen deficiency in the blood cell or tissues of the body in such degree
as to cause psychological and physiological disturbances. Anoxia may
result from a scarcity of oxygen in the air being breathed or from an
inability of the body tissues to absorb oxygen under conditions of low
ambient pressure. Also called hypoxia. Syn:oxygen deficiency
Hunt




anthill

In blast-hole drilling, the cuttings around the hole collar.
Krumlauf




anthoinite

A triclinic mineral, WAlO3 (OH)3 ; in tungstic ochers in
central Africa and Tasmania.




anthonyite

A monoclinic mineral, Cu(OH,Cl)2 .3H2 O ; lavender colored;
from the Centennial Mine in Calumet, MI. CF:calumetite




anthophyllite

An orthorhombic mineral, 4[(Mg,Fe)7 Si8 O22 (OH) (sub
2) ] ; amphibole group; commonly lamellar or fibrous, green to
clove-brown; in schists from metamorphosed ultramafic rocks; a nonspinning
grade of asbestos.




anthra

From Greek anthrax, coal; also, a precious stone; combining forms used
commonly to denote substances resembling or derived from coal, or fossils
found in coal measures. Standard, 2




anthracene

Obtained by the distillation of coal tar. Used in the manufacture of
dyestuffs. Crispin




anthracene oil

A heavy green oil that distills from coal tar above 270 degrees C and is
the principal source of anthracene, phenanthrene, and carbozole.
Webster 3rd




anthracite

a. A hard, black lustrous coal containing a high percentage of fixed
carbon and a low percentage of volatile matter. Commonly referred to as
hard coal, it is mined in the United States, mainly in eastern
Pennsylvania, although in small quantities in other States. BCI
b. The rank of coal, within the anthracitic class of Classification D 388,
such that on the dry and mineral-matter-free basis, the volatile matter
content of the coal is greater than 2% but equal to or less than 8% (or
the fixed carbon content is equal to or greater than 92% but less than
98%), and the coal is nonagglomerating. ASTM
c. Coal of the highest metamorphic rank, in which fixed-carbon content is
between 92% and 98% (on a dry, mineral-matter-free basis). It is hard and
black, and has a semimetallic luster and semiconchoidal fracture.
Anthracite ignites with difficulty and burns with a short blue flame,
without smoke. Syn:hard coal; stone coal; kilkenny coal.
See also:solid smokeless fuel




anthracite-coal-base carbon refractory

A manufactured refractory comprised substantially of calcined anthracite
coal. ASTM




anthracite coal sizes

The sizes by which anthracite coal is marketed. The sizes are called
broken, egg, stove, chestnut, pea, and buckwheat. Size is graded according
to the size of round mesh a piece will pass through.




anthracite duff

In Wales, fine screenings used in making pitch-bonded briquets and for
mixing with bituminous coal to be burned in cement kilns, on chain grate
stokers, and as powdered fuel. Hess




anthracite fines

The product from an anthracite coal-preparation plant, usually below 1/8
in (3.2 mm). See also:duff; fines; grain. Nelson




anthracite silt

Minute particles of anthracite too fine to be used in ordinary combustion.
Webster 3rd




anthracitic

Pertaining to anthracite. AGI




anthracology

a. The science of coal. Tomkeieff
b. Coal petrography, a branch of geology dealing with the physical
constitution of coal in much the same way that petrography deals with the
mineral composition of rocks. It is concerned with the physical variations
in coal that make it possible to classify coal material by type.
AGI




anthracometer

An instrument for determining the amount of carbon dioxide in a mixture of
gases. Standard, 2




anthraconite

See:bituminous limestone; stinkstone; swinestone.




anthracosilicosis

Massive fibrosis of the lungs marked by shortness of breath from
inhalation of carbon and quartz dusts. Also called miner's phthisis.
See also:anthracosis




anthracosis

A deposition of coal dust within the lungs from inhalation of sooty air.
Syn:blacklung; collier's lung. CF:anthracosilicosis
See also:mining disease




anthrafilt

Anthracite used for filtration purposes. Jones, 1


anthrafine

Sizes of anthracite smaller than barley. Jones, 1




anthrasilicosis

Variant of anthracosilicosis. Webster 3rd




anthraxolite

a. A highly graphitic coal. One specimen contained 97.7% fixed carbon.
AGI
b. Anthracitelike asphaltic material occurring in veins in Precambrian
slate of the Sudbury district, ON, Can. AGI
c. Probably fragmentary coalified wood.




anthraxylon

The vitreous appearing components of coal, which in thin section are shown
to have been derived from the woody tissues of plants--such as stems,
limbs, branches, twigs, roots, including both wood and cortex--changed and
broken up into fragments of greatly varying sizes through biological
decomposition and weathering during the peat stage, and later flattened
and transformed into coal through the coalification process, but still
present as definite units. AGI




anthraxylous coal

A bright coal (composed of anthraxylon and attritus in which the
translucent cell-wall degradation matter or translucent humic matter
predominates) in which the ratio of anthraxylon to attritus is from 3:1 to
1:1. CF:attrital coal




antibreakage device

A cushioning device to reduce the impact of coal in motion against objects
with which it may come into contact, with a view to avoiding fracture of
the coal. BS, 5




anticlinal

a. Pertaining to an anticline. CF:synclinal
b. Inclining in opposite directions. Having or relating to a fold in which
the sides dip from a common line or crest. Of or pertaining to an
anticline. The opposite of synclinal. Webster 3rd
c. The crest of an anticlinal roll may be the apex of a vein. Fay
d. Said of strata assuming an arch-shaped form. Gordon




anticlinal axis

a. The medial line of an upfolded structure, from which the strata dip on
either side.
b. If a range of hills or a valley is composed of strata that on the two
sides dip in opposite directions, the imaginary line that lies between
them and toward which the strata on each side rise is called an anticlinal
axis. See also:axis




anticlinal bend

An upwardly convex flexure in which one limb dips gently toward the apex
and the other limb dips more steeply away from it. CF:unicline;
monocline. AGI




anticlinal mountain

A mountain whose geologic structure is that of an anticline.
CF:synclinal mountain




anticlinal valley

A valley that follows an anticlinal axis. The term was used as early as
1862 by C.H. Hitchcock. CF:synclinal valley




anticline

a. A fold, generally convex upward, whose core contains the
stratigraphically older rocks. Ant. syncline. See also:antiform
AGI
b. Applied to strata that dip in opposite directions from a common ridge
or axis, like the roof of a house; the structure is termed an anticline or
saddleback. AGI
c. In this type of fold (anticline) the sides or limbs of the fold
typically slope away from the plane of the axis of either side. Every
anticlinal axis pitches in two directions; i.e., toward the two ends of
the fold. AGI




anticlinorium

A series of anticlines and synclines, so grouped that taken together they
have the general outline of an arch; opposite of synclinorium.
Webster 3rd




antiferromagnetic

Spontaneous magnetic orientation of atoms with equal magnetic moments
aligned in opposite directions. Van Vlack




antiferromagnetism

A state where d electrons are ordered in an antiparallel array, giving
materials small positive values for magnetic susceptibility and weak
attraction to an external magnetic field. CF:ferrimagnetism;
ferromagnetism; superexchange.




antiform

A fold whose limbs close upward in strata for which the stratigraphic
sequence is not known. CF:anticline




antifriction bearing

A bearing consisting of an inner and outer ring, separated by balls or
rollers held in position by a cage. Nichols, 1




antigorite

A monoclinic mineral, (Mg,Fe)3 Si2 O5 (OH)4 ;
kaolinite-serpentine group; polymorphous with clinochrysotile, lizardite,
orthochrysotile, parachrysotile; greasy variegated green; used as an
ornamental stone. See also:baltimorite




antilogous

Designating the pole (end) of a pyroelectric crystal that is negative
while the crystal is being heated and positive as it cools.
CF:analogous




antimagmatist

See:transformist




antimonate

a. A salt or ester of antimonic acid; a compound containing the radical
SbO4-3 , SbO3-1 , or Sb2 O (sub 7)
-4 (diantimonate) in which antimony has a +5 valence. AGI
b. A salt containing pentavalent antimony and oxygen in the anion.
Webster 3rd
c. A mineral characterized by inclusion of antimony and oxygen; e.g.,
swedenborgite, NaBe4 SbO7 .


antimonial arsenic

A native compound of arsenic and antimony of which the antimony forms a
comparatively small part. CF:allemontite




antimonial copper

See:chalcostibite




antimonial red silver

See:pyrargyrite




antimonial silver

a. Silver ore or alloys containing variable quantities of antimony.
Bennett
b. See:dyscrasite




antimonite

a. A salt or ester of antimonious acid or antimonous acid; a compound
containing the radical SbO3-3 or SbO2-1 in
which antimony has a +3 valence. AGI
b. See:stibnite




antimonpearceite

A monoclinic mineral, (Ag,Cu)16 (Sb,As)2 S11 .
CF:arsenpolybasite




antimony

Metallic antimony is an extremely brittle metal with a flaky, crystalline
texture. Symbol, Sb. Sometimes found native, but more frequently as the
sulfide, stibnite (Sb2 S3 ). Used in semiconductors,
batteries, antifriction alloys, type metal, small arms, tracer bullets,
cable sheathing, flame-proofing compounds, paints, ceramics, glass, and
pottery. Antimony and many of its products are toxic.
Handbook of Chemistry and Physics, 3




antimony blende

See:kermesite




antimony crudum

The name given to the molten, high-grade sulfide that drains away from the
gangue residue when stibnite (antimony sulfide) is melted by liquation.
Newton, 1




antimony glance

See:stibnite




antimony ocher

Any of several native antimony oxides; e.g., stibiconite, cervantite.




antimony regulus

An impure product of the smelting process; largely antimony sulfide.
Standard, 2




antimony star

The fernlike marking on the upper surface of the metal antimony when well
crystallized. Fay




antimony trioxide

See:valentite




antinode

A point, line, or surface in a standing wave system where some
characteristic of the wave field has maximum amplitude. Antinodes, like
nodes, may be of several types, such as pressure or velocity.
ASM, 1




antipathy of minerals

The incompatibility of certain rock-forming minerals, according to the
theory of fractional crystallization, results from their being too far
apart in a crystallization sequence to be associated in such quantities as
to make up the entire rock. Thus, a rock made up of quartz and calcic
plagioclase is unknown among igneous rocks. Hess




antiperthite

An intergrowth of a sodic and a potassic feldspar, generally considered to
have formed during slow cooling by the unmixing of sodium and potassium
ions in an originally homogeneous alkalic feldspar. In an antiperthite,
the potassic member (usually orthoclase) forms thin films, lamellae,
strings, or irregular veinlets, within the sodic member (usually albite).
CF:perthite




antistatic

Descriptive of materials that normally have high insulating qualities,
e.g., rubber hoses and belts that have been rendered conductive to reduce
risk of sparks or electric shocks in mines, or other places where there is
a fire risk. Pryor, 3




antistress mineral

A term suggested for minerals such as cordierite, the feldspars, the
pyroxenes, forsterite, and andalusite, whose formation in metamorphosed
rocks is believed to be favored by conditions that are not controlled by
shearing stress, but by thermal action and by hydrostatic pressure that is
probably no more than moderate. CF:stress mineral




antithetic fault

A fault that dips in the opposite direction from the direction in which
the associated sediments dip. Opposite of synthetic fault.
Syn:antithetic shear




antithetic shear

See:antithetic fault


antitropal ventilation

Ventilation by a current of air traveling in the opposite direction to
that of the flow of mineral out of the mine.
See also:ascensional ventilation; descensional ventilation;
homotropal ventilation. BS, 8




antiturbidity overflow system

A system fitted to a drag suction hopper dredge which disperses entrained
gases from the overflow in a settling tank and discharges the degassed
overflow below the surface. The resulting plume is normally compact and
does not appear at the surface. Abbrev., ATOS. Cruickshank




antlerite

An orthorhombic mineral, 4[Cu3 SO4 (OH)4 ] ; forms
emerald to blackish-green striated crystals or parallel aggregates; may be
reniform or massive; in oxidized parts of copper veins; an ore of copper
in desert regions. Syn:vernadskite




AN-TNT slurry

Mixture of ammonium nitrate and trinitrotoluene used as an explosive.
Lewis




antofagasite

See:eriochalcite




antozonite

A dark-violet to black semiopaque variety of fluorite that emits a strong
odor when crushed; commonly causing nausea among miners, perhaps owing to
free fluorine; produced by alpha bombardment, as in the inner bands of
halos surrounding uraninite and thorite inclusions.




anvil

a. The stationary serrated jaw piece or plate of a safety clamp,
adjustable pipe wrench, or jaw-type rock crusher. Also sometimes
incorrectly used as a syn. for drive hammer. Also called anvil block;
anvil heel; anvil jaw; heel. Long
b. An iron block placed between a stamp-mill mortar box and the foundation
block; generally used in light mortars and concrete foundations.
Fay
c. In drop forging, the base of the hammer into which the sow block and
lower die part are set. ASM, 1
d. A block of steel upon which metal is forged. ASM, 1




anvil block

A massive block of cast iron placed beneath the anvils of steam and other
heavy hammers to absorb vibration. It is often embedded in masonry or
concrete. Crispin




anvil jaw

See:anvil




anvil stone

Eng. Blue building stone, forming a bed of irregular anvil-shaped blocks.
Arkell




anvil vise

A vise with an anvil on one jaw. Standard, 2




apartalite

See:zincite




apatelite

A hydrous ferric sulfate, found in yellow nodules in clay. Fay




apatite

a. Any hexagonal or monoclinic pseudohexagonal mineral with the general
formula A5 (XO4 )3 (F,Cl,OH) , where A =
(Ba,Ca,Ce,K,Na,Pb,Sr,Y) and X = (As,C,P,Si,V). Syn:calcium phosphate
b. A mineral group fluorapatite, chlorapatite, hydroxylapatite,
carbonate-fluorapatite (francolite), and carbonate-hydroxylapatite
(dahllite).




apex

a. The highest point of a vein relative to the surface, whether it crops
out or not. The concept is used in mining law. See also:apex law
AGI
b. The tip, summit, or highest point of a landform, as of a mountain;
specif. the highest point on an alluvial fan, usually the point where the
stream that formed the fan emerged from the mountain or from confining
canyon walls. Syn:culmination
c. The highest point of a stratum, as a coalbed. Standard, 2
d. The top of an anticlinal fold of strata.
e. In U.S. mining law, used to designate the highest limit of a vein.
Ballard
f. The top of an inclined haulage plane. See also:brow; landing.
Nelson
g. Point in the center of the face of a concave, noncoring bit.
Long
h. In a classifier or hydrocyclone, the underflow aperture through which
the coarser and heavier fraction of the solids in a pulp is discharged in
accordance with its minimum cross section. Pryor, 3




apex law

a. This law gives the owner of a properly located claim on a vein the
right to an indefinite extension on the dip of the vein beyond the
vertical planes through the side lines of the claim. In order to secure
this right, the owner must lay out the end lines of the claim parallel and
of substantial length. A triangular claim would have no apex right and
cannot be patented. Lewis
b. Obsolescent mining law allowing the owner of a lode to follow it in
depth, regardless of the vertical extension of the legal surface
boundaries. Pryor, 3
c. In U.S. mining law, the individual whose claim contains the apex of a
vein may follow and exploit the vein indefinitely along its dip, even if
it passes downdip under adjoining surface property lines.
Syn:law of extralateral rights




aphanesite

See:clinoclase




aphanite

Any fine-grained igneous rock whose components are not distinguishable
with the unaided eye; a rock having aphanitic texture. CF:aphanitic
Syn:cryptomere; felsite; felsitoid. AGI




aphanitic

a. Said of the texture of an igneous rock in which the crystalline
components are not distinguishable by the unaided eye; also said of a rock
or a groundmass exhibiting such texture. CF:aphanite; phaneritic.
Syn:fine-grained
b. A crystalline texture with individual crystals too small to be visible
to the unaided eye. Syn:cryptocrystalline




aphanophyre

A porphyritic igneous rock having a groundmass which the unaided eye
cannot distniguish as either crystalline or noncrystalline. CIPW




aphothonite

A steel-gray argentiferous variety of tetrahedrite. Standard, 2


aphrite

A foliated or scaly white pearly variety of calcite. Syn:earth foam;
foam spar. Standard, 2; Fay




aphrodite

See:stevensite




aphyric

Said of the texture of a fine-grained or aphanitic igneous rock that lacks
phenocrysts. Also, said of a rock exhibiting such texture. AGI




aplanachromatic lens

A lens free from both chromatic aberration and spherical aberration.
See also:achromatic




aplanatic lens

A lens free from spherical aberration. CF:aberration
See also:aplanachromatic lens




aplite

A light-colored igneous rock characterized by a fine-grained saccharoidal
(i.e., aplitic) texture. Aplites may range in composition from granitic to
gabbroic, but the term aplite with no modifier is generally understood to
mean granitic aplite, consisting essentially of quartz, potassium
feldspar, and acid plagioclase. The term, from a Greek word meaning
simple, was in use before 1823. Syn:haplite
glass manufacture. AGI




aplitic

a. Pertaining to the fine-grained and saccharoidal texture characteristic
of aplites. AGI
b. Said of an igneous rock having such a texture. AGI




aplogranite

A light-colored rock of granitic texture consisting essentially of alkali
feldspar and quartz, with subordinate biotite; muscovite may be present or
absent. CF:two-mica granite; alaskite. Holmes, 1




Apocal

A nongelatinous permissible explosive. Used in coal mining.
Bennett




Apold-Fleissner process

A method of roasting carbonate iron ore in a shaft furnace. The ore sinks
continuously down the furnace while a current of hot air or flue gas, with
a low carbon dioxide content, is passed through the body of the ore and a
current of cold air is passed upward through the lower part of the shaft,
this part acting as a cooling chamber for the ore and as a preheating flue
for the air, which rapidly oxidizes the ferrous oxide in the upper regions
of the furnace. The quantity and temperature of the hot gases and cold air
are carefully regulated, so as to keep the carbon dioxide content of the
flue gas at a minimum and thereby ensure thorough roasting of the ore at
the lowest possible temperature. A furnace roasting 181 to 408 t/d
requires about 176,400 to 220,500 kg.cal/t (736 to 923 kg.kJ/t), giving a
heat efficiency of 73%. Osborne




apomagmatic

Said of a hydrothermal mineral deposit at an intermediate distance from
its magmatic source. The term is little used. CF:telemagmatic;
cryptomagmatic. AGI




apophyllite

A mineral group, 2[KFCa4 (Si8 O20 ).8H2 O]
(fluorapophyllite) with F replaced by (OH) (hydroxyapophyllite) and K
replaced by Na (natroapophyllite); occurs in square micaceous crystals as
secondary minerals in cavities in igneous rocks. Syn:fisheye stone




apophysis

See:tongue




aporhyolite

A rhyolite, the groundmass of which was once glassy but has become
devitrified.




Appalachian coalfield

The coal-producing area extending from northern Pennsylvania to Alabama,
in and adjacent to the Appalachian Mountains.




Appalachian orogeny

a. Late Paleozoic Era diastrophism beginning perhaps in the Late Devonian
Period and continuing until the end of the Permian Period. AGI
b. A period of intense mountain-building movements in the late Paleozoic
Era, during which the deposits in the Appalachian and Cordilleran
geosynclines were folded to form the Appalachian and Palaeocordilleran
mountains. Equivalent to the Armorican and Hercynian movements in Europe.
Syn:Appalachian revolution




Appalachian revolution

See:Appalachian orogeny




apparent cohesion

a. In soil mechanics, the resistance of particles to being pulled apart,
due to the surface tension of the moisture film surrounding each particle.
Also called moisture film cohesion. Hunt
b. Cohesion in granular soils due to capillary forces.
See also:cohesion




apparent density

a. The weight (W) of an object or material divided by its exterior volume
(Ve ) less the volume of its open pores (Vp ). Apparent
density = W/(Ve - Vp ). ACSG, 2
b. Weight per apparent volume. See also:density
Van Vlack




apparent dip

The dip of a rock layer as measured in any exposed section, or direction,
not at a right angle to the strike. It is a component of, and hence always
less than, the true dip. See also:angle of dip; true dip; dip.
Stokes




apparent movement of a fault

The apparent movement observed in any chance section across a fault is a
function of several variables: the attitude of the fault; the attitude of
the disrupted strata; the attitude of the surface upon which the fault is
observed; and the true movement (net slip) along the fault. AGI


apparent plunge

The inclination of a normal projection of lineation in the plane of a
vertical cross section. CF:plunge




apparent porosity

The ratio of the volume of open pore space in a specimen to the exterior
volume.




apparent resistivity

The measured electrical resistivity between two points on the Earth's
surface, which corresponds to the sensitivity the ground would have if it
were homogeneous.




apparent specific gravity

a. Specific gravity of a rock as measured by water displacement, taking
into account the effect of sealed pore spaces as well as constituent
minerals. See also:specific gravity
b. The ratio of the weight in air of a given volume of the impermeable
portion of a permeable material (e.g., the solid matter including its
impermeable pores or voids) at a stated temperature to the weight in air
of an equal volume of distilled water at a stated temperature.
ASCE
c. This property is determined by the standard method of dividing the
weight of a rock by the weight of an equal volume of water. The term
apparent specific gravity is used because water cannot penetrate the
closed pore spaces inside the rock, and hence the specific gravity
measured by water displacement methods includes the effect of internal
pore spaces as well as that of the constituent minerals. Lewis




apparent superposition

The actual or visible order in which strata lie in any locality.
Standard, 2




apparent velocity

The velocity with which a seismic-signal wavefront appears to travel along
the surface of the Earth. It exceeds the actual velocity if the wave train
is not traveling parallel to the surface. AGI




apparent volume

True volume plus closed-pore volume. Van Vlack




apparent width

The width of a vein or other tabular formation as determined by borehole
intercepts. This width will always be greater than the true width if the
borehole intersects the vein at any direction other than perpendicular to
the surface of the vein. CF:true width




appliances of transportation

As applied to a coal mine, these include parts of the locomotive, mobile
conveyor, and elevator transportation systems for the removal of coal.




Appolt oven

An oven for the manufacture of coke, differing from the Belgian oven in
that it is divided into vertical compartments.




appraisal

The estimation or fixing of a money value on anything, such as a gemstone.
Differs from valuation and evaluation.




approach distance

The linear distance, in the direction of feed, between the point of
initial cutter contact and the point of full cutter contact.
ASM, 1




appropriation

In the mining law, the posting of notice at or near the point where the
ledge is exposed; next, the recording of the notice; next, the marking of
the boundaries. Ricketts




approved permissible flame safety lamp

A flame safety lamp that has been approved for use in gaseous coal mines.




approximate original contour

The surface configuration achieved by backfilling and grading of the mined
area so that the reclaimed area, including any terracing or access roads,
closely resembles the general surface configuration of the land prior to
mining and blends into and complements the drainage pattern of the
surrounding terrain, with all highwalls, spoil piles, and coal refuse
piles eliminated.




Apricotine

Trade name for yellowish-red, apricot-colored quartz pebbles; may be of
gem quality; near Cape May, NJ.




apron

a. A canvas-covered frame set at such an angle in a miner's rocker that
the gravel and water in passing over it are carried to the head of the
machine.
b. An amalgamated copper plate placed below a stamp battery, over which
pulp passes. The free gold contained in the pulp is amalgamated by mercury
on the plate.
c. A broad shallow vat used for evaporating. Webster 3rd
d. A receptacle or endless belt for conveying material (such as rock) by
means of a cableway and trolley. Syn:traveling apron
Webster 3rd
e. The front gate of a scraper body. Nichols, 1
f. See:morainal apron




apron conveyor

a. A series of overlapping metal plates or aprons running in an endless
chain for transferring material from one place to another. Often used to
feed raw material from a bin. ACSG, 2
b. A conveyor so contrived as to provide a moving platform on which
materials can be carried. Syn:hinged apron




apron feed

A method of feeding material forward on an articulated platform.
Nelson




apron feeder

A feeder in which the material is carried on an apron conveyor and in
which the rate of feed is adjusted either by varying the depth of material
or the speed of the conveyor, or both. See also:conveyor-type feeder
Also called plate-belt feeder; plate feeder. BS, 5




apron plate

Sheet of copper or special alloy set in front of a stamp battery and
coated with mercury to trap and amalgamate gold. Pryor, 3


apron rope

The operating rope for the blade front of a scraper. Hammond




apron wall

That part of a panel wall between the windowsill and the support of the
panel wall. ACSG, 1




apyrous

a. Not changed by extreme heat, e.g., mica; distinguished from refractory.
Standard, 2
b. Noncombustible. Webster 3rd




AQ

A letter name specifying the dimensions of bits, core barrels, and drill
rods in the A-size and Q-series wireline diamond drilling system having a
core diameter of 27 mm and a hole diameter of 48 mm. Cumming, 2




aqua ammonia

Ammonia water; esp., a solution of ammonia containing 10% ammonia by
weight.




aqua regia

A very corrosive, fuming, yellow liquid made by mixing nitric and
hydrochloric acids, usually in the proportion of one part by volume of
pure nitric acid with three parts by volume of pure hydrochloric acid.
Used in dissolving metals such as gold and platinum and in etching.
Syn:nitrohydrochloric acid; nitromuriatic acid.




aquarium test

A test conducted by detonating a standard quantity of explosives under
water and measuring both the detonation and gas pressures using
transducers; useful for evaluating the relative strengths of various
explosives. Du Pont, 2




aqueous

a. Of, or pertaining to, water. AGI
b. Made from, with, or by means of water; e.g., aqueous solutions.
AGI
c. Produced by the action of water; e.g., aqueous sediments. AGI




aqueous fusion

Melting in the presence of water, as a magma. AGI




aqueous liquor

In the ion-exchange (IX) process, the feed to the exchange columns. In
solvent extraction, the aqueous feed containing the metal values to be
extracted into the organic phase.




aquiclude

A body of relatively impermeable rock that is capable of absorbing water
slowly but does not transmit it rapidly enough to supply a well or spring.
CF:confining bed




aquifer

a. A formation, a group of ions, or a part of a formation that is water
bearing. AGI
b. A stratum or zone below the surface of the Earth capable of producing
water, as from a well. AGI
c. An underground stratum that will yield water in sufficient quantity to
be of value as a source of supply. An aquifer is not a stratum that merely
contains water, for this would apply to all strata in the ground-water
area. An aquifier must yield water. See also:aquitard
Carson, 1




aquifer test

In situ procedure, such as single-well (bail test or slug test) and
multiple-well pumping tests, used to determine hydraulic properties of an
aquifer. Freeze




aquifuge

a. Suggested by Bedier, as the opposite of aquifer. AGI
b. A rock that contains no interconnected openings or interstices and
therefore neither absorbs nor transmits water. CF:confining bed
AGI




aquitard

Low-permeability bed, in a stratigraphic sequence, of sufficient
permeability to allow movement of contaminants, and to be relevant to
regional ground-water flow, but of insufficient permeability for the
economic production of water. See also:aquifer; aquiclude.
CF:confining bed




aragonite

a. An orthorhombic mineral, 4[CaCO3 ] ; acicular, pyramidal,
tabular, reniform, columnar, or stalactitic habit; formed from hot
carbonated water in springs, cavities in basalt, or biogenetically in
shells and pearls (mother of pearl). Syn:aragon spar
b. The mineral group aragonite, cerussite, strontianite, and witherite.




aragonite sand

Sand-size grains of predominantly aragonite (CaCO3 ) found in
shallow, tropical waters. Aragonite forms by chemical precipitation in sea
water due to the presence of SO4 ions.




Aragon spar

Former name for aragonite.




aramayoite

A triclinic mineral, Ag(Sb,Bi)S2 ; iron black with perfect
cleavage; at Chocaya, Bolivia.




arbitrage

An operation that involves a purchase in one market with the simultaneous
sale of an equivalent quantity in another market, (e.g., the London Metal
Exchange and the New York Commodity Exchange), and the necessary foreign
exchange transaction to protect against any change in the parities between
the two currencies involved. Wolff




arborescent

Applied to minerals having a treelike form, esp. when fairly massive. If
the mineral formation is so thin as to resemble a painting of a tree, it
is generally called dendritic. Syn:dendriform; dendritic. Fay


arcanite

An orthorhombic mineral, K2 SO4 .




arc cutter

A device consisting of a bit attached to knuckle-jointed rods used to
drill a curved borehole or branched holes from a parent borehole.
Syn:Thompson arc cutter




arc furnace

A furnace in which material is heated either directly by an electric arc
between an electrode and the work, or indirectly by an arc between two
electrodes adjacent to the material. ASM, 1




arch

a. A portion of rock left standing at the intersection of a mine wall and
roof, to support the roof.
b. Curved roof of underground opening. See also:dome
c. A curved structural member used to span openings or recesses; also
built flat. Structurally, an arch is a piece or assemblage of pieces so
arranged over an opening that the supported load is resolved into
pressures on the side supports and practically normal to their faces.
ACSG, 1
d. A part of a furnace; a crown. ASTM
e. To heat a pot in a pot arch. ASTM
f. One of the five chambers of a brick kiln; also, the fire chamber in
certain kinds of furnaces and ovens. Webster 3rd
g. The roof of a reverberatory furnace.




arch blocks

Applied to the wooden voussoirs used in framing a timber support for the
tunnel roof, when driving a tunnel on the so-called American system. These
blocks are made of plank, superimposed in three or more layers, and a
breaking joint. Stauffer




Archean

Said of the rocks of the Archeozoic. AGI




arched

Corn. Said of the roads in a mine, when built with stones or bricks.




Archeozoic

The earlier part of Precambrian time, corresponding to Archean rocks. Also
spelled: Archaeozoic. AGI




arch forms

Forms or patterns on which sprung arch bricks are laid to ensure the
proper arch contour.




arch girder

A normal H-section steel girder bent to a circular shape. The usual form
consists of halves joined together at the crown by bolts and two
fishplates. The arch girder is usually splay legged or straight legged in
shape, but horseshoe shapes are also in use. See also:steel support;
wood stilt. Nelson




Archimedes' principle

The statement in fluid mechanics that a fluid buoys up a completely
immersed solid so that the apparent weight of the solid is reduced by an
amount equal to the weight of the fluid that it displaces. AGI




arching

a. Arch.
b. Curved support for roofs of openings in mines; constructed archways in
masonry.
c. The development of peripheral cracks around an excavation due to the
difference in stress between the skin rock and the rock in the stress
ring. See also:V-arching
d. The folding of schists, gneisses, or sediments into anticlines.
e. The transfer of stress from a yielding part of a soil or rock mass to
adjoining less yielding or restrained parts of the mass. ASCE
f. The fretting away of the periphery of a rock tunnel, usually converting
it from a rectangular to a circular or elliptical section. The effect in
the back is sometimes referred to as the "natural arch." The putting in of
a lining built to an arch shape should not be referred to as arching but
as "lining" or "putting in the arch." Spalding




arching action

The natural process by which a fractured, pulverulent, or plastic material
acquires a certain amount of ability to support itself partially through
the resolution of the vertical component of its weight into diagonal
thrust. Woodruff




arching to a weakness

See:V-arching




arch rib

The main load-bearing member of a ribbed arch. Hammond




arch set

Steel assemblies used to support mine workings. Pryor, 3




arch structure

See:abutment; pressure arch.




arcose

See:arkose




arc shear machine

See:universal machine




arc shooting

A method of refraction seismic prospecting in which the variation of
travel time (velocity) with azimuth from a shot point is used to infer
geologic structure. The term also applies to a refraction spread placed on
a circle or a circular arc with the center at the shot point. AGI




Arctic suite

A group of basaltic and associated igneous rocks intermediate in
composition between rocks of the Atlantic suite and the Pacific suite.
CF:Atlantic suite; Pacific suite. AGI


arcwall machine

See:slabbing machine




arc welding

A group of welding processes wherein coalescence is produced by heating
with an electric arc or arcs, with or without the application of pressure
and with or without the use of filler metal. Coal Age, 2




Ardeer double-cartridge test

See:sensitivity to propagation




ardennite

a. A yellow to yellowish-brown vanadiosilicate of aluminum and manganese
that crystallizes in the orthorhombic system. Fay
b. An orthorhombic mineral, Mn4 (Al,Mg)6 (SiO4 ) (sub
2) (Si3 O10 )[(As,V)O4 ](OH)6 .




areal geology

The branch of geology that pertains to the distribution, position, and
form of the areas of the Earth's surface occupied by different types of
rock or by different geologic units, and to the making of geologic maps.
Fay




areal map

A geologic map showing the horizontal area or extent of rock units exposed
at the surface. AGI




areal pattern

A dispersion pattern resulting from widespread rock alteration. Such
patterns may outline the boundaries of a group of deposits and thus limit
the area that it is necessary to prospect in detail.




area of airway

In mine ventilation, the cross-sectional area of the entry or duct through
which the air flows; expressed in square meters.




area of influence of a well

The area surrounding a well within which the piezometric surface has been
lowered when pumping has produced the maximum steady rate of flow.
ASCE




area of settlement

The surface area affected by subsidence. Briggs




arenaceous

Said of a sediment or sedimentary rock consisting wholly or in part of
sand-sized fragments, or having a sandy texture or the appearance of sand;
pertaining to sand or arenite. Also said of the texture of such a sediment
or rock. The term implies no special composition and should not be used as
a syn. of siliceous. Syn:sandy




areng

A Bornean term for a yellowish gravelly earth, sometimes containing
diamonds.




arenite

a. A general name for sedimentary rocks composed of sand-sized fragments
irrespective of composition; e.g., sandstone, graywacke, arkose, and
calcarenite. AGI
b. A clean sandstone that is well sorted, contains little or no matrix
material, and has a relatively simple mineralogic composition; specif. a
pure or nearly pure, chemically cemented sandstone containing less than
10% argillaceous matrix and inferred to represent a slowly deposited
sediment well-washed by currents.---Etymol: Latin arena, sand. Adj.
arenitic. See also:lutite




Arents tap

An arrangement by which molten lead from the crucible of a shaft furnace
is drawn through an inverted siphon into an exterior basin from which it
can be ladled without disturbing the furnace. Syn:siphon tap
Fay




arfvedsonite

A monoclinic mineral, Na3 (Fe+2 ,Mg)4 Fe+3
Si8 O22 (OH)2 , of the amphibole group; dark green to
black; in silica-poor igneous rocks.




Argall furnace

A reverberatory roasting furnace the hearth of which has a reciprocating
movement whereby the ore is caused to move forward by the action of
rabbles extending across the hearth. Fay




Argall tubular furnace

A tubular roasting furnace consisting of four brick-lined steel tubes 30
ft (9.1 m) long nested together inside two steel tires, which revolve upon
steel-faced carrying rolls. Fay




argental mercury

See:amalgam




argentate

a. A salt in which silver acts as an acid radical; e.g., ammonium
argentate (fulminating silver). Standard, 2
b. Having a silvery appearance. CTD




argentation

The act or process of coating or plating with silver. Standard, 2




argentiferous

Containing silver.


argentiferous galena

See:silver lead ore




argentiferous lead

Lead that contains silver. CMD




argentine

a. A lamellar variety of calcite with a pearly white luster.
b. Silver-coated white metal. Standard, 2
c. A finely divided tin moss or sponge obtained from a solution of tin by
precipitation with zinc. Standard, 2
d. Adj. pertaining to, containing, or resembling silver; silvery.
AGI




argentite

An orthorhombic mineral, Ag2 S ; isometric above 180 degrees C;
dimorphous with acanthite; massive or as coating; metallic lead-gray;
soft, sectile; sp gr, 7.3; in veins with other silver and sulfide
minerals; commonly pseudomorphous after acanthite; an important ore of
silver. Syn:silver glance; vitreous silver; argyrite.




argentojarosite

A trigonal mineral, AgFe3 (SO4 )2 (OH)6 ;
alunite group; yellow to brown-yellow.




argentopyrite

An orthorhombic mineral, AgFe2 S3 ; dimorphous with
sternbergite.




argil

a. Potter's clay; white clay. Standard, 2
b. See:aluminite




argillaceous

a. Pertaining to, largely composed of, or containing clay-size particles
or clay minerals, such as an argillaceous ore in which the gangue is
mainly clay; esp. said of a sediment (such as marl) or a sedimentary rock
(such as shale) containing an appreciable amount of clay. Syn:clayey
See also:argillic
b. Pertaining to argillite. AGI




argillaceous hematite

A brown to deep-red variety of natural ferric oxide containing an
appreciable portion of clay (or sand). Syn:ironstone clay




argillaceous limestone

A limestone containing an appreciable amount (but less than 50%) of clay;
e.g., cement rock. AGI




argillaceous ore

Ore in which the gangue is mainly clay. Osborne




argillaceous rock

A sedimentary rock composed of clay-grade particles; i.e., composed of
minute mineral fragments and crystals less than 0.002 mm in diameter;
containing much colloidal-size material. In addition to finely divided
detrital matter, argillaceous rocks consist essentially of illite,
montmorillonite, kaolinite, gibbsite, and diaspore. CMD




argillation

The development of clay minerals by the weathering of aluminum silicates.
CF:kaolinization




argillic

Pertaining to clay or clay minerals; e.g., argillic alteration in which
certain minerals of a rock are converted to minerals of the clay group.
CF:argillaceous




argillite

A compact rock, derived either from mudstone (claystone or siltstone), or
shale, that has undergone a somewhat higher degree of induration than
mudstone or shale but is less clearly laminated and without its fissility,
and that lacks the cleavage distinctive of slate. AGI




argillization

The replacement or alteration of feldspars to form clay minerals, esp. in
wall rocks adjacent to mineral veins. CF:kaolinization




argon

A colorless, odorless, monatomic, inert gas. Symbol, Ar. Obtained by the
fractionation of liquid air. Used in electric light bulbs and in
fluorescent tubes. Handbook of Chemistry and Physics, 3




argulite

A variety of asphaltic sandstone. Tomkeieff




argyrite

Former name for argentite; also called argyrose.




argyrodite

An orthorhombic mineral, Ag8 GeS6 ; pseudocubic; forms a
series with canfieldite.




argyropyrite

A discredited term for a silver-iron sulfide, probably argentopyrite.


argyrose

Former name for argentite.




argyrythrose

Former name for pyrargyrite.




arite

A nickel mineral between nickeline and breithauptite in composition.




arithmetic-mean particle diameter

A measure of the average particle size obtained by summing the products of
the size-grade midpoints times the frequency of particles in each class,
and dividing by the total frequency. AGI




Arizona ruby

A deep-red or ruby-colored variety of pyrope garnet of igneous origin,
Southwestern United States.




arizonite

a. A hexagonal mineral, Fe2 Ti3 O9 ; in irregular
metallic steel-gray masses in pegmatite veins near Hackberry, AZ. Formerly
called pseudorutile.
b. A mixture of hematite, rutile, ilmenite, and anatase. AGI
c. An ore of micaceous iron, silver iodide, gold, iron sulfides, and
antimony in a vein in Yavapai County, AZ. AGI
d. A hypabyssal rock with 80% quartz, 18% alkali feldspar, and accessory
mica and apatite in Arizona (not a rock name in the IUGS classification).
AGI




Arkansas diamond

A diamond from Murfreesboro, AR.




Arkansas stone

A variety of novaculite found in the Ouachita Mountains of western
Arkansas. Also, a whetstone made of Arkansas stone.
See also:novaculite




arkansite

A brilliant, iron-black variety of brookite from Magnet Cove, AR.
Fay




arkose

A feldspar-rich sandstone, typically coarse-grained and pink or reddish,
that is composed of angular to subangular grains that may be either poorly
or moderately well sorted; usually derived from the rapid disintegration
of granite or granitic rocks, and often closely resembles granite; e.g.,
the Triassic arkoses of the Eastern United States. Quartz is usually the
dominant mineral, with feldspar (chiefly microcline) constituting at least
25%. Cement (silica or calcite) is commonly rare, and matrix material
(usually less than 15%) includes clay minerals (esp. kaolinite), mica, and
iron oxide; fine-grained rock fragments are often present. Arkose is
commonly a current-deposited sandstone of continental origin, occurring as
a thick, wedge-shaped mass of limited geographic extent (as in a fault
trough or a rapidly subsiding basin); it may be strongly cross-bedded and
associated with coarse granite-bearing conglomerate, and it may denote an
environment of high relief and vigorous erosion of strongly uplifted
granitic rocks in which the feldspar was not subjected to prolonged
weathering or transport before burial. Arkose may also occur at the base
of a sedimentary series as a thin blanketlike residuum derived from and
resting on granitic rock. Etymol: French, probably from Greek archaios,
ancient, primitive. Syn:arkosic
subarkose. Also spelled arcose. AGI




arkose quartzite

See:arkosite




arkosic

Having the character of arkose.




arkosic sandstone

A sandstone with considerable feldspar, such as one containing minerals
derived from coarse-grained quartzo-feldspathic rocks (granite,
granodiorite, gneiss) or from highly feldspathic sedimentary rocks;
specif. a sandstone containing more than 25% feldspar and less than 20%
matrix material of clay, sericite, and chlorite. See also:arkosite
AGI




arkosite

A quartzite with a notable amount of feldspar. Syn:arkose quartzite
See also:arkosic sandstone




arm

The inclined member or leg of a set or frame of timber.




armangite

A trigonal mineral, Mn26 As18 O50 (OH)4 (CO
3 ) ; black; near Laangban, Sweden.




arm conveyor

A conveyor consisting of an endless belt, or one or more chains, to which
are attached projecting arms, or shelves, for handling packages or objects
in a vertical or inclined path.




armenite

a. A hexagonal mineral, BaCa2 Al6 Si9 O30 .2H
2 O ; osumilite group.
b. Former name for azurite, Armenian stone.




armor

An outer cable covering that may be either metallic or nonmetallic.




armored apron

An apron in which each pan is provided with a separate wearing plate.




armored cable

A cable that is wrapped with metal, usually steel wires or tapes,
primarily for physical protection. See also:cable


armored flexible conveyor

A heavy, chain-type flexible conveyor capable of being advanced with the
face without dismantling. It is designed either to carry a coal cutter or
a cutter loader or to guide and hold a plow against the face. It may be
advanced by horizontal hydraulic rams that are fixed at about 20-ft (6-m)
intervals on the waste side of the conveyor. It is often employed on
prop-free-front faces with hand filling, and it has a capacity of about
200 to 300 st/hr. Syn:Panzer conveyor
chain conveyor; face conveyor. Nelson




armored relict

An unstable relict enveloped by a crystal or by a reaction shell which
revented its reaction with the other constituents of the rock.
See also:unstable relict




Armstrong air breaker

See:compressed-air blasting




arnimite

Orthorhombic Cu5 (SO4 )2 (OH)6 .3H2 O ;
perhaps the mineral antlerite.




arochlors

Chlorinated diphenyl materials that are useful as vehicles for pigments
used in glass decoration since they volatilize without leaving a carbon
residue. Arochlors provide a grinding and dispersing medium for nonaqueous
slurries of pigments and ceramic bodies; also, they can be used in
combination with waxes to provide moisture-proof coatings. Lee




aromatic compound

A compound derived from the hydrocarbon benzene, C6 H6 ,
distinguished from that derived from methane, CH4 .
Standard, 2




aromatic hydrocarbon

A compound of carbon and hydrogen that contains in its molecular structure
a closed and saturated ring of carbon atoms; e.g., benzene, naphthalene,
and anthracene. Hackh




aromatite

A bituminous stone resembling a fragrant gum resin in color and odor. It
was a precious stone in ancient Arabia and Egypt. AGI




arquerite

A soft, malleable, silver-rich variety of amalgam containing about 87%
silver and 13% mercury; from Coquimbo, Chile.




arrastra

See:arrastre




arrastre

A circular rock-lined pit in which broken ore is pulverized by stones
attached to horizontal poles fastened in a central pillar and dragged
around the pit. Also spelled arrastra. Weed, 2; CTD




arrested decay

A stage in coal formation when biochemical action ceases.
Tomkeieff




arrester

a. Any mechanical contrivance or device used to stop or slow up motion.
Crispin
b. Mechanism for the purification of a gas stream that may contain
suspended liquids or solids. Bennett




arrival dealings

Dealing in ores, concentrates, and metals in transit from source to
market. Pryor, 3




arrojadite

A monoclinic mineral, KNa4 CaMn4 Fe10 Al(PO4 )
12 (OH,F) ; dark green, forms a series with dickinsonite.




arrow

A sharp-pointed, thin metal rod about 1 to 2 ft (0.3 to 0.6 m) long with a
ring at the other end, used in surveying; a thin metal peg. Mason




arroyo

a. A term applied in the arid and semiarid regions of the Southwestern
United States to the small, deep, flat-floored channel or gully of an
ephemeral stream, usually with vertical or steeply cut banks of
unconsolidated material at least 60 cm high; it is usually dry, but may be
transformed into a temporary watercourse or short-lived torrent after
heavy rainfall. CF:dry wash
b. The small intermittent stream or rivulet that occupies such a
channel.---Etymol: Spanish, stream, brook; gutter, watercourse of a
street. See also:wadi; nullah. AGI




arsenargentite

Possibly a silver arsenide.




arsenate

a. A salt or ester of an arsenic acid; a compound containing one of the
three radicals in which arsenic has a +5 valence: ortho-arsenate, AsO (sub
4) ; meta-arsenate, AsO3 ; pyro-arsenate, As2 O7 .
b. A mineral characterized by pentavalent arsenic and oxygen; e.g.,
mimetite Pb5 (AsO4 )3 Cl . CF:vanadate




arsenic

A metallic, steel-gray, brittle element. Symbol, As. Found native in
realgar and orpiment, and combined with heavy metals. Used in bronzing,
pyrotechny, insecticides, and poisons, and as a doping agent in
transistors. Gallium arsenide is used as a laser material to convert
electricity directly into coherent light. Arsenic and its compounds are
poisonous. Handbook of Chemistry and Physics, 3




arsenical antimony

See:allemontite


arsenical nickel

See:nickeline; niccolite.




arsenical pyrite

See:arsenopyrite




arsenic bloom

See:arsenolite; pharmacolite.




arsenicite

See:pharmacolite




arsenic trioxide

A white, odorless, tasteless powder; AsO3 . Used in the manufacture
of pigments, glass, and other arsenic compounds, ceramic enamels, and
aniline colors; mixed with soda ash for boiler compounds.
Syn:white arsenic; arsenious oxide. CCD, 2




arsenious oxide

See:arsenic trioxide




arsenite

A mineral characterized by trivalent antimony and oxygen; e.g., trigonite,
Pb3 Mn(AsO3 )2 (AsO2 (OH).




arsenobismite

A yellowish-green mineral, Bi2 (AsO4 )(OH)3 .




arsenoclasite

An orthorhombic mineral, Mn5 (AsO4 )2 (OH)4 ;
red, from Laangban, Sweden. Also spelled arsenoklasite.




arsenolamprite

An orthorhombic mineral arsenic; dimorphous with arsenic.




arsenolite

An isometric mineral, As2 O3 ; dimorphous with claudetite.
Syn:arsenic bloom




arsenopyrite

a. A monoclinic mineral, 8[FeAsS] ; pseudo-orthorhombic, prismatic, and
metallic silver-white to steel gray; the most common arsenic mineral and
principal ore of arsenic; occurs in many sulfide ore deposits,
particularly those containing lead, silver, and gold. Syn:mispickel;
arsenical pyrite; white pyrite; white mundic.
b. The mineral group arsenopyrite, glaucodot, gudmundite, osarsite, and
ruarsite.




arsenosulvanite

An isometric mineral, Cu3 (As,V)S4 ; forms a series with
sulvanite. Syn:lazarevicite




arsenpolybasite

A monoclinic mineral, (Ag,Cu)16 (As,Sb)2 S11 . Also
spelled arsenopolybasite. CF:antimonpearceite




arsenuranocircite

Syn:heinrichite It is not clear which name has priority as applied to a
natural mineral. See also:metaheinrichite




arsenuranylite

The orthorhombic mineral, Ca(UO2 )4 (AsO4 )2
(OH)4 .6H2 O ; typically orange-red.




arterial road

A main road with secondary roads joining it. Hammond




artesian

a. Refers to ground water under sufficient hydrostatic head to rise above
the aquifer containing it. AGI
b. Pertaining to underground water that is confined by impervious rock or
other material under sufficient pressure to raise it above the upper level
of the saturated rock or other material in which it occurs, if this rock
or material is penetrated by wells or natural fissures. Formerly, the term
was applied only to water under sufficient pressure to raise it to the
surface of the Earth. Stokes




artesian aquifer

An aquifer that contains artesian water. AGI




artesian basin

A geologic structural feature or a combination of such features in which
water is confined under artesian pressure. AGI




artesian discharge

The process of discharge from a well by artesian pressure, and also the
quantity of water discharged. The artesian pressure is aided by the
buoyancy of the natural gas that enters some wells with the water.
Stokes


arsenical nickel

See:nickeline; niccolite.




arsenical pyrite

See:arsenopyrite




arsenic bloom

See:arsenolite; pharmacolite.




arsenicite

See:pharmacolite




arsenic trioxide

A white, odorless, tasteless powder; AsO3 . Used in the manufacture
of pigments, glass, and other arsenic compounds, ceramic enamels, and
aniline colors; mixed with soda ash for boiler compounds.
Syn:white arsenic; arsenious oxide. CCD, 2




arsenious oxide

See:arsenic trioxide




arsenite

A mineral characterized by trivalent antimony and oxygen; e.g., trigonite,
Pb3 Mn(AsO3 )2 (AsO2 (OH).




arsenobismite

A yellowish-green mineral, Bi2 (AsO4 )(OH)3 .




arsenoclasite

An orthorhombic mineral, Mn5 (AsO4 )2 (OH)4 ;
red, from Laangban, Sweden. Also spelled arsenoklasite.




arsenolamprite

An orthorhombic mineral arsenic; dimorphous with arsenic.




arsenolite

An isometric mineral, As2 O3 ; dimorphous with claudetite.
Syn:arsenic bloom




arsenopyrite

a. A monoclinic mineral, 8[FeAsS] ; pseudo-orthorhombic, prismatic, and
metallic silver-white to steel gray; the most common arsenic mineral and
principal ore of arsenic; occurs in many sulfide ore deposits,
particularly those containing lead, silver, and gold. Syn:mispickel;
arsenical pyrite; white pyrite; white mundic.
b. The mineral group arsenopyrite, glaucodot, gudmundite, osarsite, and
ruarsite.




arsenosulvanite

An isometric mineral, Cu3 (As,V)S4 ; forms a series with
sulvanite. Syn:lazarevicite




arsenpolybasite

A monoclinic mineral, (Ag,Cu)16 (As,Sb)2 S11 . Also
spelled arsenopolybasite. CF:antimonpearceite




arsenuranocircite

Syn:heinrichite It is not clear which name has priority as applied to a
natural mineral. See also:metaheinrichite




arsenuranylite

The orthorhombic mineral, Ca(UO2 )4 (AsO4 )2
(OH)4 .6H2 O ; typically orange-red.




arterial road

A main road with secondary roads joining it. Hammond




artesian

a. Refers to ground water under sufficient hydrostatic head to rise above
the aquifer containing it. AGI
b. Pertaining to underground water that is confined by impervious rock or
other material under sufficient pressure to raise it above the upper level
of the saturated rock or other material in which it occurs, if this rock
or material is penetrated by wells or natural fissures. Formerly, the term
was applied only to water under sufficient pressure to raise it to the
surface of the Earth. Stokes




artesian aquifer

An aquifer that contains artesian water. AGI




artesian basin

A geologic structural feature or a combination of such features in which
water is confined under artesian pressure. AGI




artesian discharge

The process of discharge from a well by artesian pressure, and also the
quantity of water discharged. The artesian pressure is aided by the
buoyancy of the natural gas that enters some wells with the water.
Stokes artesian leakage

The slow percolation of water from artesian formations into the confining
materials of a less permeable but not of a strictly impermeable character.
Such percolation causes a reduction in artesian pressure, depending on the
relative impermeability of the materials in the confining formations.
AGI




artesian spring

A spring, the water from which issues under artesian pressure, generally
through some fissure or other opening in the confining bed that overlies
the aquifer. AGI




artesian water

a. Ground water that is under sufficient pressure to rise above the level
at which it is encountered by a well, but that does not necessarily rise
to or above the surface of the ground. AGI
b. Ground water that is confined within a permeable bed and that rises
under pressure to approx. the height of the intake. If the outlet (well or
spring) is appreciably below the height of the intake, the water will flow
out under pressure. If even with or above the height of the intake, the
water will rise in the well but it will not flow out. Bateman, 2




artesian well

a. A well in which the water level rises above the top of the aquifer,
whether or not the water flows at the land surface. AGI
b. Formerly, only applied to a well drilled to a depth where, owing to the
structure of the strata, the water pressure was high enough to raise the
water to the surface. Standard, 2
c. Often applied to any deep well, even where pumping is necessary, as in
an ordinary driven well. See also:well




arthurite

a. An apple-green monoclinic mineral, CuFe2 (AsO4 ,PO (sub
4) ,SO4 )2 (O,OH)2 .4H2 O .
b. The mineral group arthurite, earlshannonite, ojuelaite, and
whitmoreite.




articulite

See:itacolumite




artificial aging

Aging above room temperature. See also:precipitation heat treatment
ASM, 1




artificial brine

Brine produced from an underground deposit of salt or other soluble rock
material in the process of solution mining. CF:brine




artificial horizon

A device for indicating the horizontal, as a bubble, gyroscope, pendulum,
or the flat surface of a liquid. It is sometimes simply called a horizon.
Syn:false horizon




artificial island

An island that is constructed by humans rather than formed by natural
means, usually in waters less than 30 m deep. In the mining industry they
are commonly used to support the construction of service or ventilation
shafts for underground mines extending offshore. Cruickshank




artificial liquid fuel

Fuel created by the hydrogenation of coal; the destructive distillation of
coal, lignite, or shale at low temperature; and by a recombination of the
constituents of water gas in the presence of a suitable catalyst.




artificial refractories

Materials manufactured in electric furnaces and used for special purposes;
e.g., zirconium carbide, titanium carbide, and silicon carbide.
Newton, 1




artinite

A snow-white monoclinic mineral, Mg2 (CO3 )(OH)2 .3H
2 O .




asbestiform

Said of a mineral that is fibrous, i.e., like asbestos.




asbestine

a. A silicate of magnesium much used in paint. It serves as an aid in
holding paint pigment in solution and in binding paint films together.
Also marketed under such names as French chalk and talc. Syn:agalite
Crispin
b. Of, pertaining to, or having the characteristics of asbestos;
incombustible. Webster 3rd




asbestos

a. A commercial term applied to silicate minerals that separate readily
into thin, strong fibers that are flexible, heat resistant, and chemically
inert, thus making them suitable for uses (as in yarn, cloth, paper,
paint, brake linings, tiles, insulation, cement, fillers, and filters)
where incombustible, nonconducting, or chemically resistant material is
required. Since the early 1970's, there have been serious enviromental
concerns about the potential health hazards of asbestos products, which
has resulted in strong enviromental regulations.
b. Any asbestiform mineral of the serpentine group (chrysotile, best
adapted for spinning and the principal variety in commerce) or amphibole
group (esp. actinolite, anthophyllite, gedrite, cummingtonite, grunerite,
riebeckite, and tremolite).
c. A term strictly applied to asbestiform actinolite. Syn:asbestus;
amianthus; earth flax; mountain flax; rock wool.




asbestosis

A lung disease caused by breathing asbestos dust. Harrington




asbestos minerals

Certain minerals that have a fibrous structure, are heat resistant and
chemically inert, possess high electrical insulating qualities, and are of
sufficient flexibility to be woven. The two main groups are serpentine and
amphiboles. Asbestos proper is actinolite. Chrysotile is fibrous
serpentine; amosite is fibrous anthophyllite; crocidolite is fibrous
soda-amphibole. Used in fireproof buildings, insulating, paint materials,
brake linings, and clutches, and as insulation against heat, electricity,
and acid. Pryor, 3




asbestos yarn

Yarn consisting of asbestos fiber; asbestos and vegetable fibers; asbestos
and vegetable fibers and wire; or asbestos and vegetable fibers with an
insert of cotton or other yarn reinforcement. Metallic asbestos yarn is
yarn consisting of plain asbestos yarn twisted with brass, copper, or
other fine wire. Hess




asbestus

See:asbestos




asbolan

A hexagonal mineral, (Co,Ni)1-y (MnO2 )2-x (OH) (sub
2-2y+2x) .nH2 O ; a soft, black, earthy aggregate commonly classed
as a variety of "wad," the cobalt content reaching as high as 32% (40%
cobalt oxide). Syn:asbolane; asbolite; black cobalt; cobalt ocher; wad.


asbolane

A form of wad; a soft, earthy manganese dioxide, containing up to about
32% cobalt oxide. Sometimes referred to as earthy cobalt. Syn:asbolite;
cobalt ocher. See also:asbolan




asbolite

See:asbolan; asbolane.




ascensional ventilation

A mine ventilation system in which the fresh intake air flows down to the
bottom end of the workings and then ascends along the faces to the main
return. See also:descensional ventilation; antitropal ventilation;
homotropal ventilation.




ascension theory

A theory of hypogene mineral-deposit formation involving mineralizing
solutions rising through fissures from magmatic sources in the Earth's
interior. CF:descension theory




ascharite

See:szaibelyite




aschisite

An igneous rock with the same chemical composition as its parent magma,
i.e., undifferentiated. CF:diaschistic




aschistic

Said of the rock of a minor intrusion that has a composition equivalent to
that of the parent magma, i.e., in which there has been no significant
differentiation. CF:diaschistic




ash

a. The inorganic residue after burning, esp. of coal. Ignition generally
alters both the weight and the composition of the inorganic matter.
See also:ash yield; extraneous ash; inherent ash. AGI
b. Fine pyroclastic material (under 2.0-mm diameter; under 0.063-mm
diameter for fine ash). The term usually refers to the unconsolidated
material but sometimes is also used for its consolidated counterpart,
tuff. Syn:dust; volcanic ash; volcanic dust; pumicite. AGI
c. Inorganic residue remaining after ignition of combustible substances,
determined by definite prescribed methods. ASTM




ashcroftine

A tetragonal mineral, K5 Na5 (Y,Ca)12 Si28 O
70 (OH)2 (CO3 )8 .3H2 O ; occurs in
small pink needles at Narsarsuk, Greenland.




ash curve

A graph that shows a relation between the specific gravity of fractions of
a coal sample floated in liquids of step-by-step increased density, and
the percentage of ash in each such fraction. Syn:tromp curve
Pryor, 3




ash drawers

Early name applied to tourmaline because of its polar electrostatic
property.




ash error

The difference between the percentage ash of a product of a separation and
that shown by the washability curve (based on the reconstituted feed) of a
product with the same properties (usually percentage of ash).
BS, 5




ash fusibility

A measure, in terms of temperature, of fusion of coal ash prepared and
tested under standard conditions. BS, 4




ash-fusion temperature

The temperature at which a special test cone made from particles of ash
obtained from the coal will (1) begin to deform, i.e., soften, or (2)
completely deform or fuse into a blob. Nelson




ashlar

Rectangular pieces of stone of nonuniform size that are set randomly in a
wall. AGI




ash-specific gravity curve

The curve obtained from the float-and-sink analysis by plotting the ash
contents of successive fractions against specific gravity. BS, 5




ashstone

An indurated deposit of fine volcanic ash. AGI




ash yield

The percentage of material remaining after a fuel is burned; that portion
of a laboratory sample remaining after heating under standard conditions
to constant weight; i.e., until all the combustible matter has been burned
away. See also:ash; extraneous ash; inherent ash. Nelson




asparagolite

See:asparagus stone




asparagus stone

A yellow-green variety of apatite. Syn:asparagolite




aspect

a. The gross or overall lithologic or biologic characteristics of a
stratigraphic unit as expressed at any particular point. AGI
b. The angle made by a target with the line joining it to the observation
point is known as the aspect of the target. Hunt


asperolite

A variety of chrysocolla, containing more than the usual percentage of
water.




asphaltic

Pertaining to or containing asphalt; e.g., asphaltic limestone or
asphaltic sandstone impregnated with asphalt, or asphaltic sand
representing a natural mixture of asphalt with varying proportions of
loose sand grains. AGI




asphaltic ore

Asphaltlike ore carrying invisible uranium values. Ballard




asphaltic rock

Any rock naturally impregnated with asphalt. It is generally sandstone or
limestone.




asphaltite

Any one of the naturally occurring black solid bitumens that are soluble
in carbon disulfide and fuse above 230 degrees F (110 degrees C). Examples
are uintahite, glance pitch, and grahamite. AGI




asphalt rock

A porous rock, such as a sandstone or limestone, that is impregnated
naturally with asphalt. Syn:asphalt stone; rock asphalt. AGI




asphalt stone

See:asphalt rock




asphyxiate

To suffocate; to choke. Mason




aspirating

See:dedusting




aspirator

An apparatus for moving or collecting gases, liquids, or granular
substances by suction. Webster 3rd




assay

a. To analyze the proportions of metals in an ore; to test an ore or
mineral for composition, purity, weight, or other properties of commercial
interest. Syn:crucible assay
b. The test or analysis itself; its results. AGI




assay balance

A very sensitive balance used in the assaying of gold, silver, etc., for
weighing the beads. It usually has magnifying lenses for reading the
graduations. See:balance




assayer

Person who analyzes ores and alloys, esp. bullion, to determine the value
and properties of their precious metals. DOT




assay foot

In determining the assay value of an orebody, the multiplication of its
assay grade by the number of feet along which the sample was taken.
CF:assay inch; assay value. AGI




assay grade

The percentage of valuable constituents in an ore, determined from assay.
CF:assay value; value. AGI




assay inch

In determining the assay value of an orebody, the multiplication of its
assay grade by the number of inches along which the sample was taken.
CF:assay foot; assay value. AGI




assay office

A laboratory for examining ores, usually gold and silver ores, in order to
determine their economic value. Standard, 2




assay plan

Map of a mine showing the assay, stope, width, etc., of samples taken from
positions marked. Used to control grade and quality of ore mined and
milled. Pryor, 3




assay plan factor

In sampling, a term used to describe the rate that the head value bears to
the mine sampling. This percentage figure is useful in reducing any extant
or subsequent mine-sampling average to that which in actual production it
will likely prove to be. In South Africa this is generally known as the
"mine call factor." Syn:correction factor




assay split

Agreed average value, as between buyer's and seller's assay, used as
pricing basis in sale of mineral. Pryor, 3




assay ton

A weight of 29.166+ g, used in assaying to represent proportionately the
assay value of an ore. Because it bears the same ratio to 1 mg that a ton
of 2,000 lb bears to the troy ounce, the weight in milligrams of precious
metal obtained from an assay ton of ore equals the number of ounces to the
ton. Abbrev. AT. AGI


assay value

a. The quantity of an ore's valuable constituents, determined by
multiplying its assay grade or percentage of valuable constituents by its
dimensions. CF:assay inch; assay foot. The figure for precious metals
is generally given in troy ounces per ton of ore, or per assay ton.
See also:assay grade; value. AGI
b. The monetary value of an orebody, calculated by multiplying the
quantity of its valuable constituents by the market price.
Syn:average assay value




assay walls

The outer limits to which an orebody can be profitably mined, the limiting
factor being the metal content of the country rock as determined from
assays. Hess




assembled stone

Any stone constructed of two or more parts of gem materials, whether
genuine, synthetic, imitation, or a combination thereof; e.g., a doublet
or triplet. Syn:composite stone; imitation.




assembly rod

An external bolt holding a machine together. Nichols, 1




assessment

See:assessment work




assessment drilling

Drilling done to fulfill the requirement that a prescribed amount of work
be done annually on an unpatented mining claim to retain title.
Long




assessment labor

Refers to the annual labor required of the locator of a mining claim after
discovery (and not to work done before discovery). Ricketts




assessment work

The annual work upon an unpatented mining claim on the public domain
necessary under U.S. law for the maintenance of the possessory title
thereto. This work must be done each year if the claim is to be held
without patenting. Syn:assessment; location work. Lewis




asset

Property with cash sale value. In mining, the dominant asset is the proved
ore reserve. Pryor, 3




assigned protection factor

a. The expected workplace level of respiratory protection that would be
provided by a properly functioning respirator or a class of respirators to
properly fitted and trained users. Abbrev. APF. ANSI
b. The minimum anticipated protection provided by a properly functioning
respirator or class of respirators to a given percentage of properly
fitted and trained users. NIOSH




assimilation

The incorporation and digestion of solid or fluid foreign material, such
as wall rock, in magma. The term implies no specific mechanisms or
results. Such a magma, or the rock it produces, may be called hybrid or
contaminated. See also:hybridization
Syn:magmatic assimilation; magmatic dissolution. AGI




assistant mine foreman

A person employed to assist the mine foreman in the performance of his or
her duties and to serve in his or her place, in the absence of the mine
foreman.




Assmann psychrometer

A wet-and-dry-bulb hygrometer in which air is drawn over the thermometer
bulbs by an integral fan. BS, 8




association

See:rock association




association placer location

A placer location made by an association of persons in one location
covering 160 acres (64 ha) is not eight locations covering 20 acres (8 ha)
each. It is in law a single location, and as such a single discovery is
sufficient to support such a location; the only assessment work required
is as for a single claim. Ricketts




assured mineral

See:reserves




astatic

Not taking a fixed or definite position or direction; as an instrument in
which a negative restoring force has been applied so as to aid any
deflecting force, thereby rendering the instrument more sensitive and/or
less stable. AGI




astatic gravimeter

A gravity meter or gravimeter constructed so that a high sensitivity is
achieved at certain positions of the elements of the system; i.e.,
equilibrium between a negative restoring force and the force of gravity at
such positions. See also:gravimeter




astatic pendulum

A pendulum having almost no tendency to take a definite position of
equilibrium. AGI




astatization

The application of a restoring force to a moving element of a physical
system in such a manner as to drive the moving element away from its rest
position and to aid any deflecting force, so as to increase sensitivity.
AGI




asteria

Any gemstone that, when cut en cabochon in the correct crystallographic
direction, displays a rayed figure (a star) by either reflected or
transmitted light; e.g., star sapphire. Syn:star stone
See also:star sapphire


asteriated

a. Like a star, with rays diverging from a center.
b. Said of a mineral, crystal, or gemstone that exhibits asterism; e.g.,
asteriated beryl. See:star




asteriated quartz

Quartz having whitish or colored radiations within the crystals.
See:star quartz




asteriated topaz

Asteriated yellow variety of corundum, wrongly called Oriental topaz.
Schaller




asterism

a. Starlike rays of light observed in some minerals when viewed from
certain directions, particularly if the mineral is cut en cabochon.
Minerals having this feature are called asteriated or star. Asteriated
beryl, chrysoberyl, crocidolite, emerald, quartz, ruby, and sapphire are
known. Hess
b. A starlike effect observed in certain minerals either by transmitted or
by reflected light. AGI
c. Elongation of Laue X-ray diffraction spots produced by stationary
single crystals as a result of internal crystalline deformation. The size
of the Laue spot is determined by the solid angle formed by the normals to
any set of diffracting planes; this angle increases with increasing
crystal deformation, producing progressively elongated (asteriated) spots.
Measurements of asterism are used as indicators of deformation in crystals
subjected to slow stress or to shock waves. CF:corundum cat's eye




asthenolith

A body of magma that was formed by melting in response to heat generated
by radioactive disintegration. AGI




asthenosphere

The layer or shell of the Earth below the lithosphere, which has reduced
yield strength, permitting viscous or plastic flow under relatively small
stresses; it is a zone in which isostatic adjustments take place, magmas
may be generated, and seismic waves are strongly attenuated. It is a part
of the upper mantle. Syn:zone of mobility
AGI




ASTM coal classification

A system based on proximate analysis in which coals containing less than
31% volatile matter on the mineral-matter-free basis (Parr formula) are
classified only on the basis of fixed carbon; i.e., 100% volatile matter.
They are divided into five groups: above 98% fixed carbon; 98% to 92%
fixed carbon; 92% to 86% fixed carbon; 86% to 78% fixed carbon; and 78% to
69% fixed carbon. The first three of these groups are called anthracites,
and the last two are called bituminous coals. The remaining bituminous
coals, the subbituminous coals, and the lignites are then classified into
groups as determined by the calorific value of the coals containing their
natural bed moisture; i.e., the coals as mined but free from any moisture
on the surface of the lumps. The classification includes three groups of
bituminous coals with moist calorific value from above 14,000 Btu/lb (32.5
MJ/kg) to above 13,000 Btu/lb (30.2 MJ/kg); three groups of subbituminous
coals with moist calorific value below 13,000 Btu/lb to below 8,300 Btu/lb
(19.3 MJ/kg); and two groups of lignitic coals with moist calorific value
below 8,300 Btu/lb. The classification also differentiates between
consolidated and unconsolidated lignites and between the weathering
characteristics of subbituminous and lignitic coals.
See also:coal classification systems




astochite

A blue to gray-violet variety of amphibole; at Wermland, Sweden. Locally
known as blue rhodonite. Syn:soda richterite




astrakanite

See:blodite.




astridite

An ornamental stone, consisting mainly of chromojadeite. From Manokwari,
New Guinea. English




astringent

a. A taste that puckers the mouth; descriptive of certain minerals, such
as alum. Fay
b. Causing contraction, shrinking, or puckering. Webster 3rd
c. Said of a clay containing an astringent salt.




astrophyllite

a. A triclinic mineral, (K,Na)3 (Fe,Mn)7 Ti2 Si (sub
8) O24 (O,OH)7 ; forms a series with kupletskite.
b. A mineral group.




asymmetrical

a. Without symmetry.
b. Said of mineral crystals having no center, plane, or axis of symmetry.




asymmetrical vein

A vein with unlike mineral sequences on either side.




asymmetric class

The class of crystal forms without any symmetry. Fay




asymmetric fold

A fold in which one limb dips more steeply than the other. If one limb is
overturned, the term "overturned fold" or "overfold" is used.
CF:symmetrical fold




asymmetric unit

The whole group of prototype atoms that, where repeated by the symmetry
operations of a space group, generate a crystal structure.
CF:unit cell




atacamite

An orthorhombic mineral, 4[Cu2 Cl(OH)3 ] ; trimorphous with
paratacamite and botallackite; grass green, in fine crystal aggregates,
fibrous or columnar; a supergene mineral in oxidized zones of copper
deposits in desert regions; a source of copper. Syn:remolinite




ataxic

Said of an unstratified mineral deposit. CF:eutaxic




atelestite

A monoclinic mineral, Bi8 (AsO4 )3 O5 (OH)
5 ; yellow.




at grade

See:graded


Atkinson

The resistance of a section of roadway in which there is a pressure of 1
lb/ft2 (6.9 kPa) throughout the section, when an amount of 1,000
ft3 /s (1 kilocusec or 28.3 m3 /s) of dry air at 60
degrees F (15.6 degrees C) and 30 in (762 mm) barometer is passing.
See also:Atkinson's friction coefficient




Atkinson's friction coefficient

The measure of the pressure expended per 1,000 ft/min per square foot of
surface traversed in order to create motion under the conditions
prevailing. It is expressed as pounds per square foot per 1,000 ft/min.
See also:Atkinson




Atlantic suite

One of two large groups of igneous rocks, characterized by alkalic and
alkali-calcic rocks. Harker (1909) divided all Tertiary and Holocene
igneous rocks of the world into two main groups, the Atlantic suite and
the Pacific suite, the former being so named because of the predominance
of alkalic and alkali-calcic rocks in the nonorogenic areas of crustal
instability around the Atlantic Ocean. Because there is such a wide
variety of tectonic environments and associated rock types in the areas of
Harker's Atlantic and Pacific suites, the terms are now seldom used to
indicate kindred rock types; e.g., Atlantic-type rocks are widespread in
the mid-Pacific volcanic islands. CF:Arctic suite; Mediterranean suite.
AGI




Atlas ore

See:malachite




Atlas spar

Syn:satin spar




atmosphere

a. The gaseous envelope surrounding the Earth. The mixture of gases that
surrounds the Earth, being held thereto by gravity. It consists by volume
of 78% nitrogen, 21% oxygen, 0.9% argon, 0.03% carbon dioxide, and minute
quantities of helium, krypton, neon, and xenon. The atmosphere is so
compressed by its own weight that half is within 5.5 km of the Earth's
surface. AGI
b. A unit of pressure. A normal atmosphere is equal to the pressure
exerted by a vertical column of mercury 760 mm in height at 0 degrees C,
and with gravity taken as 980.665 cm/s2 . It equals 14.66 psi
(101 kPa). AGI
c. In a furnace, the mixture of gases resulting from combustion.
d. The kind of air prevailing in any place, as within a kiln during
firing. Kinney




atmosphere-supplying respirator

A class of respirators that supply a respirable atmosphere, independent of
the workplace atmosphere. ANSI




atmospheric condenser

A condenser using water at atmospheric pressure. Strock, 2




atoll texture

a. A texture sometimes observed in a thin section of a rock, in which a
ring of one mineral occurs with another mineral or minerals inside and
outside the ring.
b. In mineral deposits, the surrounding of one mineral by a ring of one or
more other minerals; commonly results from replacement of pyrite by
another mineral, with the outermost pyrite unaffected and constituting the
"atoll." Syn:core texture




atom

According to the atomic theory, the smallest particle of an element that
can exist either alone or in combination with similar particles of the
same element or of a different element. The smallest particle of an
element that enters into the composition of a molecule.
Webster 3rd




atomic charge

Electrical charge density due to gain or loss of one or more electrons.
Pryor, 3




atomic distance

Distance between two atom centers. Pryor, 3




atomic moisture meter

A device to monitor the moisture in coal passing through a preparation
plant, by using radiation that is sensitive to hydrogen atoms. The coal is
bombarded with neutrons, some of which strike hydrogen atoms and bounce
back to a detector tube, thus providing a continuous measure of moisture
content. This meter permits the moisture content of coal to be measured
instantaneously, continuously, and automatically.




atomic number

The number of protons in the nucleus of an atom.
See also:atomic weight




atomic plane

a. Any one of the layers into which atoms form themselves in an orderly
pattern during the growth of a crystal.
b. In a crystal, any plane with a regular array of atomic units (atoms,
ions, molecules, or radicals); it has potential to diffract X-rays, to
parallel a crystal face, or to permit cleavage.




atomic scattering factor

Describes the "efficiency" of X-ray scattering of a given atom in a given
direction; equal to the amplitude of the wave scattered by an atom divided
by the amplitude of the wave scattered by one electron.




atomic susceptibility

Change in magnetic moment of 1 g.atom on application of magnetic field of
unit strength. Pryor, 3




atomic volume

a. The space occupied by a quantity of an element as compared with its
atomic weight. Obtained by dividing the specific gravity of the element by
its atomic weight; also called specific volume. Standard, 2
b. The volume occupied by 1 g.atom of an element. CTD




atomic weight

The average relative weight of the atoms of an element referred to an
arbitrary standard of 16.0000 for the atomic weight of oxygen. The atomic
weight scale used by chemists takes 16.0000 as the average atomic weight
of oxygen atoms as they occur in nature. The scale used by physicists
takes 16.00435 as the atomic weight of the most abundant oxygen isotope.
Division by the factor 1.000272 converts an atomic weight on the
physicists' scale to the corresponding atomic weight on the chemists'
scale. See also:atomic number




atomization

a. In powder metallurgy, the dispersion of a molten metal into particles
by a rapidly moving stream of gas or liquid. ASM, 1
b. A patented process for producing a metallic dust, such as zinc dust.
Fay




atomized metal powder

Metal powder produced by the dispersion of molten metal by a rapidly
moving gas, or liquid stream, or by mechanical dispersion. ASTM


atomizer

A spray device for producing a very fine mist for the suppression of
airborne dust in mines. It is normally operated by compressed air.
Syn:jet mixer; line oiler.




atopite

A yellow or brown variety of romeite containing fluorine.
See also:romeite




attached ground water

That portion of the subsurface water adhering to the pore walls. It is
assumed to be equal in quantity to the pellicular water, and it is
measured by specific retention. AGI




attack rate

Planned rate of ore extraction from mineral deposit. Pryor, 3




attapulgite

A light-green, magnesium-rich clay mineral, named from its occurrence at
Attapulgus, GA, where it is quarried as fuller's earth. Crystallizes in
the monoclinic system. Syn:palygorskite




attendance signaling system

A signaling system that operates between the surface lamp room and the
underground office, indicating the workers in attendance at the beginning
of the shift. See also:self-service system




attenuation

a. A reduction in the amplitude or energy of a signal, such as might be
produced by passage through a filter. AGI
b. A reduction in the amplitude of seismic waves, as produced by
divergence, reflection and scattering, and absorption. AGI
c. That portion of the decrease in seismic or sonar signal strength with
distance that is dependent not on geometrical divergence, but on the
physical characteristics of the transmitting medium. CF:damping
AGI




Atterberg limits

In a sediment, the water-content boundaries between the semiliquid and
plastic states (known as the liquid limit) and between the plastic and
semisolid states (known as the plastic limit).
See also:consistency limits
AGI




Atterberg scale

A proposed particle-size scale or grade scale for the classification of
sediments based on a decimal system beginning with 2 mm. The limits of the
subclass are obtained by taking the square root of the product of the
larger grade limits. The subdivision thus made follows the logarithmic
rule. This is the accepted European standard for classification of
particle size. AGI




Atterberg test

A method for determining the plasticity of clay in terms of the difference
between the water content when the clay is just coherent and when it
begins to flow as a liquid. Dodd




attitude

The relation of some directional feature in a rock to the horizontal
plane. The attitude of planar features (bedding, foliations, joints, etc.)
is described by the strike and the dip. The attitude of a linear feature
(fold axis, lineation, etc.) is described by the strike of the horizontal
projection of the linear feature and its plunge. AGI




attrital coal

A bright coal (composed of anthraxylon and of attritus in which the
translucent cell-wall degradation matter or translucent humic matter
predominates) in which the ratio of anthraxylon to attritus is less than
1:3. See also:anthraxylous coal; attritus. AGI




attrition

a. The act of wearing and smoothing of rock surfaces by the passage of
water charged with sand and gravel, by the passage of sand drifts, the
descent of glaciers, etc. AGI
b. The wear and tear that rock particles in transit undergo through mutual
rubbing, grinding, knocking, scraping, and bumping, with resulting
comminution in size. CF:abrasion




attrition mill

a. Mill that grinds abrasively, using rubbing action rather than impact
shattering to disintegrate material. Pryor, 3
b. A disintegrator depending chiefly on impact to reduce the particle size
of the charge. Attrition mills are sometimes used in the clay building
materials industry to deal with the tailings from the edge-runner mill.
Dodd




attritious wear

Wear of abrasive grains in grinding such that sharp edges gradually become
rounded. A grinding wheel that has undergone such wear usually has a
glazed appearance. ASM, 1




attritus

a. A composite term for dull gray to nearly black coal components of
varying maceral content, unsorted and with fine granular texture, that
forms the bulk of some coals or is interlayered with bright bands of
anthraxylon in others. It is formed of a tightly compacted mixture of
altered vegetal materials, esp. those that were relatively resistant to
complete degradation. CF:attrital coal
introduced by R. Thiessen in 1919. AGI
b. Thin bands of dull coal interlaminated with the bright, glossy coal
bands called anthraxylon. Microscopically it consists of intimately mixed,
tightly compacted remains of varied morphological form and origin.
Attritus is a collective term, not directly comparable with any one of the
microlitho types of the Stopes-Heerlen nomenclature but consists of an
intimate association of varying proportions of macerals of the vitrinite,
exinite, and inertinite groups. It is present in practically all types of
coal. In bright-banded coal it is secondary in importance to anthraxylon,
but in splint coal it is the dominant component, and nonbanded attrital
coals consist entirely of attritus. IHCP
c. The dull-gray to nearly black, frequently striped portion of material
that comprises the bulk of some coals, and the alternating bands of bright
anthraxylon in well-banded coals. It was derived from all sorts of
comminuted and macerated plant matter, esp. from the plants that were more
resistant to complete decomposition. It consists of humic degradation and
opaque, charred, resinous, and mineral matter; fats, oils, waxes,
cuticles, spores, arid spore exines, and other constituents of the plants
forming the coal. AGI
d. Coal components consisting of a mixture of microscopic fragments of
vegetable tissues. It is classified into opaque attritus and transparent
attritus. Generally, it corresponds to cull coal or durain.
Tomkeieff




audiofrequency

Any frequency corresponding to a normal audible sound wave (ranges roughly
from 15,000 to 20,000 Hz). Hunt




augelite

A monoclinic mineral, Al2 (PO4 )(OH)3 .




augen

In foliate metamorphic rocks such as schists and gneisses, large
lenticular mineral grains or mineral aggregates having the shape of an eye
in cross section, in contrast to the shapes of other minerals in the rock.
See also:augen structure




augen gneiss

A general term for a gneissic rock containing augen.
See also:cataclasite




augen schist

A metamorphic rock characterized by recrystallized minerals occurring as
augen or lenticles parallel to and alternating with schistose streaks.
See also:mylonite gneiss


augen structure

In some gneissic and schistose metamorphic rocks, a structure consisting
of minerals like feldspar, quartz, or garnet that have been squeezed into
elliptical or lens-shaped forms resembling eyes (augen), which are
commonly enveloped by essentially parallel layers of contrasting
constituents such as mica or chlorite. CF:augen; flaser structure.
AGI




auger

a. A drill for seismic shotholes or geophone holes modeled after the
conventional carpenter's screw auger. Hence, any seismic shothole drilling
device in which the cuttings are continuously removed mechanically from
the bottom of the bore during the drilling operation without the use of
fluids. A rotary drilling device used to drill shotholes or geophone holes
in which the cuttings are removed by the device itself without the use of
fluids. CF:hand auger; hand boring. AGI
b. Any of various augerlike tools designed for boring holes in wood or for
boring into soil and used esp. for such purposes as mining coal,
prospecting, drilling for oil or water, and digging postholes. Also, a
tool for drilling holes in coal for blasting. Webster 3rd
c. Drilling using an auger. See also:coal auger; bucket auger;
twist drill; horizontal auger. Long




auger bits

Hard steel or tungsten-carbide-tipped cutting teeth used in an auger run
on a torque bar or in an auger-drill head run on a continuous-flight
auger. Long




auger boring

The hole and/or the process of drilling a hole using auger equipment.
Long




auger head

See:auger mining




auger hole

A hole drilled with power-driven augers. Williams




auger mining

A mining method often used by strip-mine operators where the overburden is
too thick to be removed economically. Large-diameter, spaced holes are
drilled up to 200 ft (61 m) into the coalbed by an auger. Like a bit used
for boring holes in wood, this consists of a cutting head with screwlike
extensions. As the auger turns, the head breaks the coal and the screw
carries it back into the open and dumps it on an elevating conveyor; this,
in turn, carries the coal to an overhead bin or loads it directly into a
truck. Auger mining is relatively inexpensive, and it is reported to
recover 60% to 65% of the coal in the part of the bed where it is used.
Syn:auger head




augite

A monoclinic mineral, 8[(Ca,Na)(Mg,Fe,Al,Ti)(Si,Al)2 O6 ] ;
pyroxene group; dark-green to black with prismatic cleavage; a common
rock-forming mineral in igneous and metamorphic rocks. Syn:basaltine;
fassaite; pyroxene. CF:pigeonite




augite bronzite

An obsolete term for a pyroxene between enstatite and augite in
composition.




augite diorite

A diorite in which augite is a prominent mafic mineral.




augite syenite

A syenite in which augite is a prominent mafic mineral.




auralite

a. Altered iolite. Standard, 2
b. Altered cordierite.




aureole

a. A circular or crescentic distribution pattern about the source or
origin of a mineral, ore, mineral association, or petrographic feature. It
is encountered principally in magnetic and geochemical surveys.
CF:dispersion pattern
b. Discoloration of a mineral, viewed in thin section, in the form of a
ring. Most haloes of this sort are caused by radiation damage by alpha
particles emitted from uranium- and thorium-bearing mineral inclusions.
AGI
c. A zone surrounding an igneous intrusion, in which the country rock
shows the effects of contact metamorphism. Syn:contact zone;
metamorphic aureole. AGI
d. A zone of alteration or other chemical reaction surrounding a mineral
in a rock.
e. See:halo




auri-argentiferous

Applied to minerals containing both gold and silver. Standard, 2




aurichalcite

An orthorhombic mineral, 4[(Zn,Cu)5 (CO3 )2 (OH) (sub
6) ] ; forms soft scaly greenish-blue crusts in oxidized zones of
copper-zinc ore deposits; a guide to zinc ore.




auricupride

An orthorhombic mineral, Cu3 Au . Syn:gold cupride; cuproauride.




auriferous

Refers to a substance that contains gold, esp. gold-bearing mineral
deposits. AGI




auriferous pyrite

Iron sulfide, in the form of pyrite, containing gold, probably in solid
solution. CTD




aurobismuthinite

A doubtful sulfide containing bismuth, gold, and silver; lead-gray in
color. It may be a mixture of (Bi,Au,Ag2 )S , or possibly of a
gold-silver alloy, and bismuthinite, Bi2 S3 . From Nacozari,
Sonora, Mex. English




aurosmirid

A silver-white crystal solution of gold and osmium in isometric iridium.




aurostibite

An isometric mineral, AuSb2 ; pyrite group.


aurous

Of, pertaining to, or containing gold in the univalent state; e.g., aurous
chloride (AuCl).




austempering

The isothermal transformation of a ferrous alloy at a temperature below
that of pearlite formation and above that of martensite formation.
Austempering is the isothermal transformation used to form a unique
acicular matrix of bainitic ferrite and stable high-carbon austenite in
hardenable cast irons. ASM, 2




austenite

A solid solution of one or more elements in face-centered cubic iron.
Unless otherwise designated (such as nickel austenite), the solute is
generally assumed to be carbon. ASM, 1




austenitic stainless steel

The so-called 18-8 grades contain from 16% to 26% chromium and 6% to 20%
nickel, are not hardenable by heat treatment, and are nonmagnetic in the
annealed condition. Henderson




austenitizing

Forming austenite by heating a ferrous alloy into the transformation range
(partial austenitizing) or above the transformation range (complete
austenitizing). ASM, 1




austinite

An orthorhombic mineral, CaZn(AsO4 )(OH); adelite group; forms a
series with conichalcite.




Australian bentonite

Trade name for highly plastic clays from Trida, N.S.W.
New South Wales




Australian cinnabar

A variety of chrome red.




authigene

A mineral or rock constituent that was formed in place; e.g., a mineral of
an igneous rock; the cement of a sedimentary rock if deposited directly
from solution; or a mineral resulting from metamorphism.
Syn:authigenic mineral




authigenesis

a. The process by which new minerals form in place within a rock during or
after its formation, as by replacement or recrystallization, or by
secondary enlargement of quartz overgrowths. AGI
b. Any process involving crystal growth in situ, i.e., subsequent to the
origin of its matrix or surroundings but not a product of transformation
or recrystallization, customarily reserved for low-temperature sedimentary
environments. Ant. allogenesis. Adj. authigenic; authigenous. Adv.
authigenous.




authigenetic

See:authigenic




authigenic

Formed or generated in place; specif. said of rock constituents and
minerals that have not been transported or that crystallized locally at
the spot where they are now found, and of minerals that came into
existence at the same time as, or subsequently to, the formation of the
rock of which they constitute a part. The term, as used, often refers to a
mineral (such as quartz or feldspar) formed after deposition of the
original sediment. Syn:authigenetic
CF:autochthonous




authigenic mineral

See:authigene




authorized fuels

In Great Britain, under the regulations made by the Minister (Smoke
Control Areas-Authorized Fuels-Regulations, 1956), authorized fuels
include coke of all kinds, anthracite, low-volatile steam coals,
Phurnacite, Coalite, Rexco, etc., as well as oil, gas, and electricity.
Nelson




authorized person

An authorized person is either one appointed or permitted by the official
designated by State mining laws to be in charge of the operation of the
mine or one appointed to perform certain duties incident to generation,
transformation, and distribution or use of electricity in the mine. This
person shall be familiar with construction and operation of the apparatus
and with hazards involved.




autochthon

A body of rocks that remains at its site of origin, where it is rooted to
its basement. Although not moved from their original site, autochthonous
rocks may be mildly to considerably deformed. CF:allochthon;
stationary block. Also spelled autochthone. AGI




autochthonous

Formed or produced in the place where now found. Applied to a rock the
dominant constituents of which have been formed in situ; e.g., rock salt.
CF:allochthonous; authigenic. Holmes, 1




autochthonous coal

Coal believed to have been formed from accumulations of plant debris at
the place where the plants grew. Two modes of origin are distinguished:
terrestrial and aquatic. Also called indigenous coal.
See also:in situ origin theory




autochthonous peat

Peat that formed in place by the gradual accumulation of plant remains in
water. It is subdivided into low-moor peat and high-moor peat.
Tomkeieff




autochthony

An accumulation of plant remains in the place of their growth. The term
itself can be distinguished between autochthonous elements of growth
(euautochthony) and autochthonous elements of sedimentation
(hypautochthony). IHCP




autoclastic

Having a broken or brecciated structure, formed in the place where it is
found as a result of crushing, dynamic metamorphism, or other mechanical
processes; e.g., a fault breccia, or a brecciated dolomite produced by
diagenetic shrinkage followed by recementation. CF:cataclastic
AGI


autogenous

a. In the dense-media separation process, fluid media partly composed of a
mineral species selected from material being treated. Pryor, 4
b. Selectively sized lumps of material used as grinding media.
Pryor, 4




autogenous grinding

The secondary grinding of coal or ore by tumbling in a revolving cylinder
with no balls or bars taking part in the operation. Nelson




autogenous roasting

Roasting in which the heat generated by oxidation of the sulfides is
sufficient to propagate the reaction. Newton, 2




autohydration

The development of new minerals in an igneous rock by the action of its
own magmatic water on already existing magmatic minerals.
Schieferdecker




autoinjection

See:autointrusion




autointrusion

a. A process wherein the residual liquid of a differentiating magma is
injected into rifts formed in the crystallized fraction at a late stage by
deformation of unspecified origin. Syn:autoinjection
b. Sedimentary intrusion of rock material from one part of a bed or set of
beds in process of deposition into another part. AGI




autolith

a. An inclusion in an igneous rock to which it is genetically related.
CF:xenolith
b. In a granitoid rock, an accumulation of iron-magnesium minerals of
uncertain origin. It may appear as a round, oval, or elongate segregation
or clot. AGI




automatic ash analysis

Analysis in which the coal sample passes first to a conditioning unit,
which dries and grinds it, then to an X-ray analysis unit. The analysis is
based on the difference in the reflection of X-rays by the combustible and
noncombustible components of the sample. The reflection is compared
photoelectrically with a reference sample. Nelson




automatic belt takeup

A device used with certain types of belt conveyors for the taking up or
storage of belt during reversible operation. Jones, 1




automatic clip

An appliance for attaching and detaching mine trams or cars without manual
effort. It is generally attached at inby clipping stations and detached at
the shaft bottom. See also:clip; coupling; haulage clip. Nelson




automatic clutch

A clutch whose engagement is controlled by centrifugal force, vacuum, or
other power without attention by the operator. Nichols, 1




automatic coupling

A device that automatically couples cars when they bump together.
Zern




automatic cyclic winding

A system of automatic winding in which the complete installation operates
without human aid and winding continues automatically as long as coal is
available at the shaft bottom and is cleared at the bank.
Syn:cyclic winding
Ward-Leonard control; manual winding control; semiautomatic control.
Nelson




automatic dam

See:boomer




automatic door

a. A mine door operated by pressure of the locomotive wheels on a switch
along the rails approaching the doors, which closes the door automatically
after the trip has passed. These doors are preferable to regular mine
doors. However, they must be carefully maintained to keep them in a safe
operating condition.
b. A wooden door arranged to close automatically when released, by
installing the door with a slight lean in the direction of closing.




automatic doors

Air doors on a haulage road that are automatically operated by a passing
vehicle or train of tubs, or other means. BS, 8




automatic feed

a. A hydraulic-control system of valves that when once set and without the
manual assistance of a drill runner will reduce or increase feed pressure
applied to a drill stem as hardness of rock penetrated changes.
Long
b. A pneumatic rock drill equipped with a power-actuated feed mechanism.
Long




automatic feed sampler

An automatic, timed sampling device used at mill feeds and other plants.
Nelson




automatic heat-treating machine

See:Gilman heat-treating machine




automatic pump control

The starting and stopping of a pump by a mechanism actuated by the level
of water in the suction well or pump, or by the level or pressure of water
in a discharge tank. BS, 10




automatic pumping

An arrangement to stop and start a mine pump automatically by means of a
float switch. Nelson


automatic reclosing relays

Relays used to automatically reclose electrically operated circuit
breakers. They limit the duration of power failures in many instances
where faults clear themselves quickly. Most reclosing relays attempt to
close a breaker three times before locking it out. The time interval
between reclosures is predetermined. Lockout means that after the third
attempt fails to keep the breaker in, the relay will not function until it
is reset manually. Such relays can be designed to operate more than three
times before locking out, with the number of reclosures depending on the
requirements and design of the system. Coal Age, 3




automatic recorder

Appliance for recording the working time of machines such as cutter
loaders, conveyors, etc. A vibrating type, fitted on the equipment itself,
marks on a chart a straight line when the machine is idle and an
oscillating one when working. Nelson




automatic sampler

An instrument designed to take samples of mine gases or water at
predetermined times or intervals.




automatic sampling

Automatic removal of samples at timed intervals from a passing stream of
ore, pulp, or solution. Pryor, 3




automatic sprinkler

A water sprinkling device closed by a metallic alloy that melts at a low
temperature. In case of fire the alloy melts, releasing a water spray.
These devices are used in wood-lined shafts and timbered bottoms,
sometimes by legal requirements. Zern




automatic winding

This term includes at least three different systems: (1) fully automatic
winding in which no driver, banksman, or onsetter is employed; (2)
pushbutton automatic winding, similar to the above except that the
operation is started by a pushbutton by the banksman or onsetter; and (3)
cyclic winding in which the driver takes off the brakes and throws over
the control lever at the beginning of the wind. Sinclair, 5




autometamorphism

a. A process of recrystallization of an igneous rock under conditions of
falling temperature, attributed to the action of its own volatiles, e.g.,
serpentinization of peridotite or spilitization of basalt. AGI
b. The alteration of an igneous rock by its own residual liquors. This
process should rather be called deuteric because it is not considered to
be metamorphic. See also:deuteric




autometasomatism

Alteration of a recently crystallized igneous rock by its own last
water-rich liquid fraction, trapped within the rock, generally by an
impermeable chilled border. CF:autopneumatolysis; autometamorphism.
AGI




automolite

A dark-green to nearly black variety of gahnite. Schaller




automorphic

a. Said of the holocrystalline texture of an igneous or metamorphic rock,
characterized by crystals bounded by their own rational faces. Also said
of a rock with such a texture. The term idiomorphic is more common in U.S.
usage. CF:xenomorphic
b. A synonym of euhedral, obsolete in U.S. usage, but generally preferred
in European usage. Syn:automorphic-granular; euhedral. AGI




automorphic-granular

See:automorphic




autopneumatolysis

Autometamorphism involving the crystallization of minerals or the
alteration of a rock by gaseous emanations originating in the magma or
rock itself. CF:autometasomatism




autospray

A device for controlling dust carried by loaded conveyors. A liquid medium
is sprayed on the conveyor load only when moving and not when stationary,
or when the belt is running unloaded. The spray control is placed
centrally beneath the conveyor belt and a load causes the belt to deflect
and rotate the driving pulley, which causes the controller valve to open.
A belt stoppage or no load causes the valve to close. Nelson




autostoper

A stoper or light compressed-air rock drill, mounted on an air-leg support
that not only supports the drill but also exerts pressure on the drill
bit. Nelson




autotransformer

A special-type of transformer whose use in mines is limited to apparatus
for starting induction motors of the squirrel cage type. The winding is a
common one for primary and secondary, and the two circuits are
electrically in contact with each other. Mason




autotroph

Organism capable of growth exclusively at the expense of inorganic
nutrients. See also:chemolithotroph; photolithotroph.




autrometer

a. An automatic multielement-indexing X-ray spectrograph, capable of the
qualitative and quantitative determinations of as many as 24 elements in a
single sample. Choice of the elements may be made from magnesium through
all the heavier elements. The device measures the intensity of an emitted
wavelength band from a standard sample and compares it with the intensity
of a like band from an unknown sample. These data are presented in the
form of a ratio of one intensity to the other. Nelson
b. An automatic multielement-indexing X-ray spectrograph.




autunite

a. A tetragonal mineral, 2[Ca(UO2 )2 (PO4 )2
.10-12H2 O] ; radioactive; yellow to pale green; fluorescent; forms
scaly or foliated aggregates; results from oxidation or hydrothermal
alteration of uranium minerals; an ore of uranium. Syn:calcouranite
b. The mineral group autunite, fritzscheite, heinrichite, kahlerite,
novacekite, sabugalite, saleeite, sodium autunite, torbernite, troegerite,
uranocircite, uranospinite, and zeunerite.




auxiliary

a. Tools or other equipment, such as a pump, drill rods, casing, core
barrel, bits, water swivel, safety clamp, etc., required for use with a
drill machine to carry on specific drilling operations. Long
b. A helper or standby engine or unit. CF:accessory




auxiliary anode

A supplementary anode placed in a position to raise the current density on
a certain area of the cathode to get better plate distribution.
ASM, 1




auxiliary cylinder

A cylinder, operated by compressed air, that is used to assist the main
engine of a compressed-air shaker conveyor, esp. where the conveyor cannot
develop a sufficient amount of forward acceleration because of grades. The
auxiliary cylinder is attached to the conveyor by a driving chain and to a
prop by a fixing chain. Jones, 1


auxiliary fault

A branch fault. A minor fault ending against a major fault. AGI




auxiliary mineral

In Johannsen's classification of igneous rocks, any light-colored,
relatively rare mineral, or mineral occurring in small quantities, such as
apatite, muscovite, corundum, fluorite, and topaz. AGI




auxiliary operations

In metallurgy, diverse operations, such as storing in bins, conveying (by
conveyors, feeders, elevators, or pumps), sampling, weighing, reagent
feeding, and pulp distribution. Gaudin, 1




auxiliary ventilation

A method of supplementing the main ventilating current in a mine by using
a small fan to draw air from the main current and force it through canvas
or metal pipe to some particular place, such as the ends of drifts,
crosscuts, raises, entries, or other workings driven in a mine.
See also:air mover; exhaust ventilation; ventilation tubing;
forced auxiliary ventilation; overlap auxiliary ventilation; piped air;
reversible auxiliary ventilation; two-fan auxiliary ventilation.
Lewis




available alumina

The theoretical amount of extractable aluminum oxide, Al2 O3
, present in a bauxite. The amount of alumina in a bauxite that is present
in a form that allows it to be extracted by a refining plant.




available energy

That part of the total energy that can be usefully employed. In a perfect
engine, that part which is converted to work. Strock, 2




available lime

a. Those constituents of a lime that enter into a desired reaction under
the conditions of a specific method or process. ASTM
b. Represents the total free lime (CaO) content in a quicklime or hydrate
and is the active constituent of a lime. It provides a mean of evaluating
the concentration of lime. Boynton




available power

The rate at which a given source would deliver energy to a load having an
impedance that is the conjugate of the source impedance is designated as
the available power of that source. Hunt




available power loss

The available power loss of a transducer connecting an energy source and
an energy load is the transmission loss measured by the ratio of the
source power to the output power transducer. Hunt




available relief

a. The vertical distance between the altitude of the original surface
after uplift and the level at which grade is first attained. AGI
b. The relief that is available for erosion.




available silica

The amount of silica present in a flux that is not slagged by impurities
in the flux itself. Newton, 1




avalanche

A large mass of snow, ice, soil, or rock, or mixtures of these materials,
falling, sliding, or flowing very rapidly under the force of gravity.
Velocities may sometimes exceed 500 km/hr. AGI




avalanche protector

Guardplates that prevent loose material from sliding into contact with the
wheels or tracks of a digging machine. Nichols, 1




avanturine

Alternate spelling of aventurine.




aventurescence

a. A word used to describe the metallic spangled effect seen, in reflected
light, in aventurine and aventurine feldspar. A sort of schiller but more
scintillating.
b. A display of bright or strongly colored reflections from included
crystals in some translucent mineral specimens.




aventurine

a. A glass containing opaque sparkling particles of foreign material,
which is usually copper or chromic oxide. With copper particles, it is
called gold aventurine, and with chromic oxide particles, it is called
chrome aventurine or green aventurine. A glass containing gold-colored
inclusions. Webster 3rd; AGI
b. A translucent quartz that is spangled throughout with scales of mica or
of some other mineral. Syn:aventurine quartz
c. As an adj., having the brilliant spangled appearance of aventurine.
Applied esp. to transparent or translucent quartz or feldspar containing
shiny inclusions. Webster 3rd; AGI
d. A variety of albite with reddish reflections from exsolved hematite in
certain planes. See also:goldstone




aventurine feldspar

Orthoclase, albite, or oligoclase that is more or less transparent, with
fiery reflections from enclosed flat mineral particles, which are probably
hematite or goethite. Sunstone is aventurine oligoclase. Hess




aventurine glass

A glass supersaturated with either iron, chromium, or copper oxide (or a
combination of the oxides) that is melted and cooled under controlled
conditions to cause the excessive oxides to crystallize, forming platelike
crystals or spangles. See also:goldstone




aventurine quartz

See:aventurine




average assay value

See:assay value




average clause

Eng. A clause that, in granting leases of minerals (coal, ironstone, and
clay in particular), provides that lessees may, during every year of the
term, make up any deficiency in the quantity of coal, etc., stipulated to
be worked, so as to balance the dead or minimum rent.


average loading

The average number of tons of a specified material to be carried by a
conveyor per hour, based on total operating-shift tonnage. NEMA, 2




avicennite

An isometric mineral, Tl2 O3 ; black; forms minute crystals.




AW

Letter name specifying the dimensions of bits, core barrels, and drill
rods in the A-size and W-group wireline diamond drilling system having a
core diameter of 30.1 mm and a hole diameter of 48 mm. Syn:AX
Cumming, 2




awaruite

An isometric mineral, Ni2 Fe to Ni3 Fe .
Syn:native nickel-iron




AX

Letter name specifying the dimensions of core, core barrels, and casing in
the A-size and X-series wireline diamond drilling system having a core
diameter of 30.1 mm and a hole diameter of 48 mm. The AX designation for
coring bits has been replaced by the AW designation. Syn:AW
Cumming, 2




axes

a. Crystallographic directions through a crystal; used as lines of
reference. Hurlbut
b. Reference coordinates a, b, c, in crystallography, crystallographic
axes.
c. Directions of apparent isotropy in anisotropic crystals, optic axes.
d. Elements of rotational symmetry, symmetry axes.
e. In ellipsoids representing the Fletcher indicatrix of refractive
indices, semiaxes represent optic directions. Singular: axis. Also called
optic axes.




axial angle

a. The acute angle between the two optic axes of a biaxial crystal. Its
symbol is 2V. AGI
b. The axial angle in air (symbol 2E) is the larger angle between the
optic axes after being refracted on leaving the crystal. AGI
c. See:optic angle




axial compression

In experimental work with cylinders, a compression applied parallel with
the cylinder axis. It should be used in an appropriate sense only in the
interpretation of deformed rocks. AGI




axial element

In crystallography, the ratio of a unit distance along a crystallographic
axis and the corresponding angle between axes. Syn:lattice parameter




axial figure

a. The interference figure that is obtained in convergent light when an
optic axis of the mineral being observed in thin section or as a fragment
coincides with the axis of the polarizing microscope. When a thin section
of a uniaxial mineral that was cut at right angles to an optic axis is
examined between crossed nicols (that is, between two polarizers, the
polarization planes of which are at right angles to each other) an
equal-armed shadowy cross and a series of spectrally colored, circular
bands are seen. If the mineral is biaxial, two shadowy parabolic curves
called isogyres and opening away from each other in a series of spectrally
colored, oval bands appear. Hess
b. In polarized light microscopy, an interference figure in which an optic
axis is centered in the field of view.




axial flow

In pumping or in ventilation, the use of a propeller or impeller to
accelerate the load along the axis of the impeller. Pryor, 3




axial-flow compressor

A compressor in which air is compressed in a series of stages as it flows
axially through a decreasing tubular area. Pryor, 3




axial-flow fan

a. A type of mine fan in which the mine air enters along the axis parallel
to the shaft and continues in this direction to the point of exhaust. The
axial-flow fan may have fixed blades (fixed-pitch fan) or adjustable
blades (variable-pitch fan). Two, four, or six aerofoil section blades
(like an aircraft wing) are usually employed. Also called a screw fan.
CF:radial-flow fan; mixed-flow fan.
See also:contra-rotating axial fan; mine-ventilation fan.
b. The compressed-air auxiliary fan consists essentially of a single-stage
axial-flow fan in which the rotor also forms the rotor of a compressed-air
turbine. The exhaust from the turbine is added to the ventilating air. The
result is a light and very compact machine, capable of the same duties as
the smaller sizes of electric auxiliary fans. Roberts, 1




axial line

See:axis




axial plane

a. A more or less planar surface that intersects a fold in such a manner
that the limbs of the fold are symmetrically arranged with reference to
it.
b. The plane of the optic axes of an optically biaxial crystal.
c. A crystallographic plane that includes two crystallographic axes.
AGI
d. Of geologic structures, a plane that intersects the crest of the trough
or a fold such that the limbs, or sides, of the fold are more or less
symmetrically arrayed with reference to it.




axial-plane cleavage

Cleavage that is closely related to the axial planes of folds in the rock,
either being rigidly parallel to the axes, or diverging slightly on each
flank (fan cleavage). Most axial-plane cleavage is closely related to the
minor folds seen in individual outcrops, but some is merely parallel to
the regional fold axes. Most axial-plane cleavage is also slaty cleavage.
AGI




axial-plane folding

Large-scale secondary folding of preexisting folds, in response to
stresses that varied considerably from those that caused the original
folding. The axial planes of the original folds are folded. AGI




axial-plane foliation

Foliation that developed parallel to the axial plane of a fold and
perpendicular to the principal deformational pressure. AGI




axial-plane separation

The distance between axial surfaces of adjacent antiforms and synforms
where the folds occur in the same layer or surface. AGI




axial priming

A system for priming blast agents in which a core of priming material
extends through most or all of the blasting agent charge length.




axial ratio

The lengths of crystallographic axes defined in terms of their ratios
with, by convention, a set at unity where one axis is unique and b set at
unity where all three axes are required.


axial stream

a. The main stream of an intermontane valley, which flows along the lowest
part of the valley and parallel to its long dimension, in
contradistinction to the streams that flow down the mountains on either
side.
b. A stream that follows the axis of an anticline or a syncline.




axial trace

The intersection of the axial plane of a fold with the surface of the
Earth or any other specified surface.




axinite

a. The mineral group ferroaxinite, magnesioaxinite, manganaxinite, and
tinzenite.
b. Triclinic borosilicates with the formula A3 Al2 BSi (sub
4) O15 (OH) where A = (Ca,Fe,Mg,Mn). Syn:glass schorl




axiolite

A term proposed by Zirkel for a variety of elongated spherulite in which
there is an aggregation of minute acicular crystals arranged at right
angles to a central axis rather than from a point.




axis

a. The central or dominating region of a mountain chain, or the line that
follows the crest of a range and thus indicates the most conspicuous part
of the uplift.
b. The centerline of a tunnel. Nichols, 1
c. Intersection of the axial plane of a fold with a particular bed; axial
line.
d. A straight line about which a body or a three-dimensional figure
rotates or may be supposed to rotate; a straight line with respect to
which a body, figure, or system of points is either radially or
bilaterally symmetrical. Webster 3rd
e. In crystallography, one of the imaginary lines in a crystal that are
used as coordinate of axes of reference in determining the positions and
symbols of the crystal planes. CF:crystallographic axes;
coordinate system.
f. Often used synonymously with anticlinal; thus, the Brady's bend axis
for Brady's bend anticlinal. See also:anticlinal axis; synclinal axis.
g. The trace of the axial surface of a fold on the fold profile plane
(obsolete).
h. A line that follows the trend of large landforms, e.g., the crest of a
ridge or mountain range, or the bottom or trough of a depression. Plural:
axes.




axis of acoustic symmetry

For many transducers, the three-dimensional directivity is such that it
may be represented by the surface generated by rotating a two-dimensional
directivity pattern about the axis corresponding to the reference bearing
of the transducer. This axis may then be described as an axis of acoustic
symmetry or as the acoustic axis. Hy




axis of symmetry

An imaginary line in a crystal, crystal structure, or crystal lattice,
about which it may be rotated to an identical configuration. If identity
occurs once during a complete rotation of 360 degrees , the axis is a
monad, twice a diad, thrice a triad, four times a tetrad, or six times a
hexad. Syn:symmetry axis




axonometric projection

A method of projection which has the advantage of containing a true plan,
and can therefore be set up from drawings already in existence for other
purposes. The plan is turned through 45 degrees , vertical lines being
drawn from the angles on the plan to show the elevations.
See also:oblique projection; isometric projection. Hammond




axotomous

In crystallography, having cleavage perpendicular to an axis; said of
minerals. Standard, 2




axstone

A variety of nephrite jade. Also spelled axestone.




azimuth

Direction of a horizontal line as measured on an imaginary horizontal
circle, the horizontal direction reckoned clockwise from the meridian
plane of the observer, expressed as the angular distance between the
vertical plane passing through the point of observation and the poles of
the Earth and the vertical plane passing through the observer and the
object under observation. In the basic control surveys of the United
States, azimuths are measured clockwise from south, a practice not
followed in all countries. CF:bearing




azorite

A variety of altered zircon. See:zircon




Aztec stone

a. A greenish variety of smithsonite.
b. A green variety of turquoise.




azulinhas

Small cloudy sapphires occuring with diamonds in Brazil.




azurchalcedony

See:azurlite




azure

See:lapis lazuli; lazurite.




azure malachite

See:azurmalachite




azure quartz

See:sapphire quartz




azure spar

See:azurite; lazulite.




azure stone

A term applied to lapis lazuli (lazurite) and to other blue minerals such
as lazulite and azurite.




azurite

a. A monoclinic mineral, 2[Cu3 (OH)2 (CO3 )2 ];
forms vitreous azure crystals; a supergene mineral in oxidized parts of
copper deposits associated with malachite; an ore of copper.
Syn:azure spar; chessylite; blue copper; blue copper ore;
blue malachite.
b. A compact semiprecious stone derived from compact azurite and used as a
decorator material.
c. A trade name for a sky-blue gem variety of smithsonite.


azurite malachite

See:azurmalachite




azurlite

Chalcedony colored blue by chrysocolla; and used as a gemstone.
Syn:azurchalcedony




azurmalachite

An intimate mixture or intergrowth of azurite and malachite, commonly
massive and concentrically banded; used as an ornamental stone.
Syn:azure malachite; azurite malachite.