Uranium Miner's Glossary of uranium mining and
general mining terms
C D E F
G H I J
K L M N
O P Q R
S T U V
W X Y Z
Acidic precipitation - Snow and
rain that have a low pH, caused by sulphur dioxide and nitric
oxide gases from industrial activity released into the
Acidic rocks - Igneous rock carrying a high (greater than
65%) proportion of silica.
Acid mine drainage - Acidic run-off water from mine waste
dumps and mill tailings ponds containing sulphide minerals. Also
refers to ground water pumped to surface from mines.
Adit - An opening driven horizontally into the side of a
mountain or hill for providing access to a mineral deposit.
Aerial magnetometer - An instrument used to measure
magnetic field strength from an airplane.
Aeromagnetic survey - A geophysical survey using a
magnetometer aboard, or towed behind, an aircraft.
Agglomerate - A breccia composed largely or entirely of
fragments of volcanic rocks.
Agglomeration - A method of concentrating valuable
minerals based on their adhesion properties.
Agitation - In metallurgy, the act or state of being
stirred or shaken mechanically, sometimes accomplished by the
introduction of compressed air.
Airborne survey - A survey made from an aircraft to
obtain photographs, or measure magnetic properties,
Alloy - A compound of two or more metals.
Alluvium - Relatively recent deposits of sedimentary
material laid down in river beds, flood plains, lakes, or at the
base of mountain slopes. (adj. alluvial)
Alpha meter - An instrument used to measure positively
charged particles emitted by radioactive materials.
Alpha ray - A positively charged particle emitted by
certain radioactive materials.
Alteration - Any physical or chemical change in a rock or
mineral subsequent to its formation. Milder and more localized
Amorphous - A term applied to rocks or minerals that
possess no definite crystal structure or form, such as amorphous
Amortization - The gradual and systematic writing off of
a balance in an account over an appropriate period.
Amphibolite - A gneiss or schist largely made up of
amphibole and plagioclase minerals.
ANFO - Acronym for ammonium nitrate and fuel oil, a
mixture used as a blasting agent in many mines.
Annual report - The formal financial statements and
report on operations issued by a corporation to its shareholders
after its fiscal year-end.
Anode - A rectangular plate of metal cast in a shape
suitable for refining by the electrolytic process.
Anomaly - Any departure from the norm which may indicate
the presence of mineralization in the underlying bedrock.
Anthracite - A hard, black coal containing a high
percentage of fixed carbon and a low percentage of volatile
Anticline - An arch or fold in layers of rock shaped like
the crest of a wave.
Apex - The top or terminal edge of a vein on surface or
its nearest point to the surface.
Ash - The inorganic residue remaining after ignition of
Assay - A chemical test performed on a sample of ores or
minerals to determine the amount of valuable metals contained.
Assay foot (metre, inch, centimetre) - The assay
value multiplied by the number of feet, metres, inches,
centimetres across which the sample is taken.
Assay map - Plan view of an area indicating assay values
and locations of all samples taken on the property.
Assessment work - The amount of work, specified by mining
law, that must be performed each year in order to retain legal
control of mining claims.
Authorized capital - see capital stock.
Autogenous grinding - The process of grinding ore in a
rotating cylinder using large pieces of the ore instead of
conventional steel balls or rods.
Back - The ceiling or roof of an
Backfill - Waste material used to fill the void created
by mining an orebody.
Background - Minor amounts of radioactivity due not to
abnormal amounts of radioactive minerals nearby, but to cosmic
rays and minor residual radioactivity in the vicinity.
Back sample - Rock chips collected from the roof or back
of an underground opening for the purpose of determining grade.
Backwardation - A situation when the cash or spot price
of a metal stands at a premium over the price of the metal for
delivery at a forward date.
Balance sheet - A formal statement of the financial
position of a company on a particular day, normally presented to
shareholders once a year.
Ball mill - A steel cylinder filled with steel balls into
which crushed ore is fed. The ball mill is rotated, causing the
balls to cascade and grind the ore.
Banded iron formation - A bedded deposit of iron
Basalt - An extrusive volcanic rock composed primarily of
plagioclase, pyroxene and some olivine.
Basal till - Unsorted glacial debris at the base of the
soil column where it comes into contact with the bedrock below.
Basement rocks - The underlying or older rock mass. Often
refers to rocks of Precambrian age which may be covered by
Base camp - Centre of operations from which exploration
activity is conducted.
Base metal - Any non-precious metal (eg. copper, lead,
zinc, nickel, etc.).
Basic rocks - Igneous rocks that are relatively low in
silica and composed mostly of dark-colored minerals.|
Batholith - A large mass of igneous rock extending to
great depth with its upper portion dome-like in shape. Similar,
smaller masses of igneous rocks are known as bosses or plugs.
Bauxite - A rock made up of hydrous aluminum oxides; the
most common aluminum ore.
Bear market - Term used to describe market conditions
when share prices are declining.
Bedding - The arrangement of sedimentary rocks in layers.
Beneficiate - To concentrate or enrich; often applied to
the preparation of iron ore for smelting.
Bentonite - A clay with great ability to absorb water and
which swells accordingly.
Bessemer - An iron ore with a very low phosphorus
Bio-leaching - A process for recovering metals from
low-grade ores by dissolving them in solution, the dissolution
being aided by bacterial action.
Biotite - A platy magnesium-iron mica, common in igneous
Bit - The cutting end of a drill frequently
made of an extremely hard material such as industrial diamonds
or tungsten carbide.
Blackjack - A miner's term for sphalerite (zinc sulphide).
Black smoker - Volcanic vent found in areas of active
ocean floor spreading, through which sulphide-laden fluids
Blaster - A mine employee responsible for loading,
priming and detonating blastholes.
Blast furnace - A reaction vessel in which mixed charges
of oxide ores, fluxes and fuels are blown with a continuous
blast of hot air and oxygen-enriched air for the chemical
reduction of metals to their metallic state.
Blasthole - A drill hole in a mine that is filled with
explosives in order to blast loose a quantity of rock.
Blister copper - A crude form of copper (assaying about
99%) produced in a smelter, which requires further refining
before being used for industrial purposes.
Block caving - An inexpensive method of mining in which
large blocks of ore are undercut, causing the ore to break or
cave under its own weight.
Board lot - One hundred shares.
Bond - An agreement to pay a certain amount of interest
over a given period of time.
Boom - A telescoping, hydraulically powered steel arm on
which drifters, manbaskets and hydraulic hammers are mounted.
Box hole - A short raise or opening driven above a drift
for the purpose of drawing ore from a stope, or to permit
Break - Loosely used to describe a large-scale regional
shear zone or structural fault.
Breast - A working face in a mine, usually restricted to
Breccia - A rock in which angular fragments are
surrounded by a mass of fine-grained minerals.
Broken reserves - The ore in a mine which has been broken
by blasting but which has not yet been transported to surface.
Brunton compass - A pocket compass equipped with sights
and a reflector, used for sighting lines, measuring dip and
carrying out preliminary surveys.
Bulk mining - Any large-scale, mechanized method of
mining involving many thousands of tonnes of ore being brought
to surface per day.
Bulk sample - A large sample of mineralized rock,
frequently hundreds of tonnes, selected in such a manner as to
be representative of the potential orebody being sampled. Used
to determine metallurgical characteristics.
Bullion - Metal formed into bars or ingots.
Bull market - Term used to describe financial market
conditions when share prices are going up.
Bull quartz - A prospector's term for white,
coarse-grained, barren quartz.
Byproduct - A secondary metal or mineral product
recovered in the milling process.
Cable bolt - A steel cable, capable
of withstanding tens of tonnes, cemented into a drillhole to
lend support in blocky ground.
Cage - The conveyance used to transport men and equipment
between the surface and the mine levels.
Calcine - Name given to concentrate that is ready for
smelting (i.e. the sulphur has been driven off by oxidation).
Call - An option to buy shares at a specified price. The
opposite of a "put".
Capitalization - A financial term used to describe the
value financial markets put on a company. Determined by
multiplying the number of outstanding shares of a company by the
current stock price.
Capital stock - The total ownership of a limited
liability company divided among a specified number of shares.
Captive stope - A stope that is accessible only through a
Carbon-in-pulp - A method of recovering gold and silver
from pregnant cyanide solutions by adsorbing the precious metals
to granules of activated carbon, which are typically ground up
Cash flow - The net of the inflow and outflow of cash
during an accounting period. Does not account for depreciation
or bookkeeping write-offs which do not involve an actual cash
Cathode - A rectangular plate of metal, produced by
electrolytic refining, which is melted into commercial shapes
such as wirebars, billets, ingots, etc.
Cesium magnetometer - An geophysical instrument which
measures magnetic field strength in terms of vertical gradient
and total field.
Chalcocite - A sulphide mineral of copper common in the
zone of secondary enrichment.
Chalcopyrite - A sulphide mineral of copper and iron; the
most important ore mineral of copper.
Change house - The mine building where workers change
into work clothes; also known as the "dry".
Channel sample - A sample composed of pieces of vein or
mineral deposit that have been cut out of a small trench or
channel, usually about 10 cm wide and 2 cm deep.
Charter - A document issued by a governing authority
creating a company or other corporation.
Chartered bank - A financial institution that accepts
deposits and provides loans.
Chip sample - A method of sampling a rock exposure
whereby a regular series of small chips of rock is broken off
along a line across the face.
Chromite - The chief ore mineral of chromium.
Chute - An opening, usually constructed of timber and
equipped with a gate, through which ore is drawn from a stope
into mine cars.
Cinnabar - A vermilion-colored ore mineral of mercury.
Circulating load - Over-sized chunks of ore returned to
the head of a closed grinding circuit before going on to the
next stage of treatment.
Claim - A portion of land held either by a prospector or
a mining company. In Canada, the common size is 1,320 ft. (about
400 m) square, or 40 acres (about 16 ha).
Clarification - Process of clearing dirty water by
removing suspended material.
Classifier - A mineral-processing machine which separates
minerals according to size and density.
Clay - A fine-grained material composed of hydrous
Cleavage - The tendency of a mineral to split along
Closed circuit - A loop in the milling process wherein a
selected portion of the product of a machine is returned to the
head of the machine for finishing to required specification.
Coal - A carbonaceous rock mined for use as a fuel.
Coalification - The metamorphic processes of forming
Collar - The term applied to the timbering or concrete
around the mouth of a shaft; also used to describe the top of a
Column flotation - A milling process, carried out in a
tall cylindrical column, whereby valuable minerals are separated
from gangue minerals based on their wetability properties.
Common stock - Shares in a company which have full voting
rights which the holders use to control the company in common
with each other. There is no fixed or assured dividend as with
preferred shares, which have first claim on the distribution of
a company's earnings or assets.
Complex ore - An ore containing a number of minerals of
economic value. The term often implies that there are
metallurgical difficulties in liberating and separating the
Cone crusher - A machine which crushes ore between a
gyrating cone or crushing head and an inverted, truncated cone
known as a bowl.
Concentrate - A fine, powdery product of the milling
process containing a high percentage of valuable metal.
Concentrator - A milling plant that produces a
concentrate of the valuable minerals or metals. Further
treatment is required to recover the pure metal.
Confirmation - A form delivered by a broker to the
client, setting forth the details of stock sales or purchases
for the client.
Conglomerate - A sedimentary rock consisting of rounded,
water-worn pebbles or boulders cemented into a solid mass.
Contact - A geological term used to describe the line or
plane along which two different rock formations meet.
Contact metamorphism - Metamorphism of country rocks
adjacent to an intrusion, caused by heat from the intrusion.
Contract-specified price - The delivery price determined
when a contract is signed. It can be a fixed price or a base
price escalated according to a given formula.
Contango - A situation in which the price of a metal for
forward or future delivery stands at a premium over the cash or
spot price of the metal.
Continuous miner - A piece of mining equipment which
produces a continuous flow of ore from the working face.
Controlled blasting - Blasting patterns and sequences
designed to achieve a particular objective. Cast blasting, where
the muck pile is cast in a particular direction, and deck
blasting, where holes are loaded once but blasted in successive
blasts days apart, are examples.
Conventional mill (uranium) - A facility
engineered and built principally for processing of uraniferous
ore materials mined from the earth and the recovery, by chemical
treatment in the mill’s circuits, of uranium and/or other valued
coproduct components from the processed ore.
Converter - In copper smelting, a furnace used to
separate copper metal from matte.
Core - The long cylindrical piece of rock, about an inch
in diameter, brought to surface by diamond drilling.
Core barrel - That part of a string of tools in a diamond
drill hole in which the core specimen is collected.
Cordillera - The continuous chain of mountain ranges on
the western margin of North and South America.
Cost model for undiscovered resources - A computerized
algorithm that uses the uranium endowment estimated for a given
geological area and selected industry economic indexes to
develop random variables that describe the undiscovered
resources ultimately expected to be discovered in that area at
chosen forward-cost categories.
Country rock - Loosely used to describe the general mass
of rock adjacent to an orebody. Also known as the host rock.
Crosscut - A horizontal opening driven from a shaft and
(or near) right angles to the strike of a vein or other orebody.
Crust - The outermost layer of the Earth; includes both
continental and oceanic crust.
Cum-dividend - Buyer entitled to pending dividend
Current assets - Assets of company which can and are
likely to be converted into cash within a year. Includes cash,
marketable securities, accounts receivable and supplies.
Current liabilities - A company's debts that are payable
within a year's time.
Custom smelter - A smelter which processes concentrates
from independent mines. Concentrates may be purchased or the
smelter may be contracted to do the processing for the
Cut-and-fill - A method of stoping in which ore is
removed in slices, or lifts, and then the excavation is filled
with rock or other waste material (backfill), before the
subsequent slice is extracted.
Cutoff grade - The lowest grade, in percent U3O8, of
uranium ore at a minimum specified thickness that can be mined
at specified cost.
Cut value - Applies to assays that have been reduced to
some arbitrary maximum to prevent erratic high values from
inflating the average.
Cyanidation - A method of extracting exposed gold or
silver grains from crushed or ground ore by dissolving it in a
weak cyanide solution. May be carried out in tanks inside a mill
or in heaps of ore out of doors.
Cyanide - A chemical species containing carbon and
nitrogen used to dissolve gold and silver from ore.
Day order - An order to buy or sell
shares, good only on the day the order was entered.
Debenture - See bonds.
Debt financing - Method of raising capital whereby
companies borrow money from a lending institution.
Deck - The area around the shaft collar where men and
materials enter the cage to be lowered underground.
Decline - A sloping underground opening for machine
access from level to level or from surface; also called a ramp.
Deferred charges - Expenses incurred but not charged
against the current year's operation.
Depletion - An accounting device, used primarily in tax
computations. It recognizes the consumption of an ore deposit, a
mine's principal asset.
Depreciation - The periodic, systematic charging to
expense of plant assets reflecting the decline in economic
potential of the assets.
Development - Underground work carried out for the
purpose of opening up a mineral deposit. Includes shaft sinking,
crosscutting, drifting and raising.
Development drilling - drilling to establish accurate
estimates of mineral reserves. Drilling done to determine more
precisely size, grade, and configuration of an ore deposit
subsequent to the time the determination is made that the
deposit can be commercially developed.
Diabase - A common basic igneous rock usually occurring
in dykes or sills.
Diamond - The hardest known mineral, composed of pure
carbon; low-quality diamonds are used to make bits for diamond
drilling in rock.
Diamond drill - A rotary type of rock drill that cuts a
core of rock that is recovered in long cylindrical sections, two
cm or more in diameter.
Diamond driller - A person who operates a diamond drill.
Dilution (mining) - Rock that is , by necessity, removed
along with the ore in the mining process, subsequently lowering
the grade of the ore.
Dilution (of shares) - A decrease in the value of a
company's shares caused by the issue of treasury shares.
Diorite - An intrusive igneous rock composed chiefly of
sodic plagioclase, hornblende, biotite or pyroxene.
Dip - The angle at which a vein, structure or rock bed is
inclined from the horizontal as measured at right angles to the
Dip needle - A compass with the needle mounted so as to
swing in a vertical plane, used for prospecting to determine the
magnetic attraction of rocks.
Directional drilling - A method of drilling involving the
use of stabilizers and wedges to direct the orientation of the
Discount - The minimum price below the par value at which
treasury shares may legally be sold.
Disseminated ore - Ore carrying small particles of
valuable minerals spread more or less uniformly through the host
Dividend - Cash or stock awarded to preferred and common
shareholders at the discretion of the company's board of
Dividend claim - Made when a dividend has been paid to
the previous holder because stock has not yet been transferred
to the name of the new owner.
Domestic - Domestic means within the 50 States, District
of Columbia, Puerto Rico, the Virgin Islands, Guam, and other
U.S. Possessions. The word “domestic” is used also in
conjunction with data and information that are compiled to
characterize a particular segment or aspect of the uranium
industry in the United States.
Domestic purchase - A uranium purchase from a firm
located in the United States.
Domestic sale - A uranium sale to a firm located in the
Domestic uranium industry - Collectively, those businesses
(whether U.S. or foreign-based) that operate under the laws and
regulations pertaining to the conduct of commerce within the
United States and its territories and possessions and that
engage in activities within the United States, its territories,
and possessions specifically directed toward uranium
exploration, development, mining, and milling; marketing of
uranium materials; enrichment; fabrication; or acquisition and
management of uranium materials for use in commercial nuclear
Dor bar - The final saleable product of a gold mine.
Usually consisting of gold and silver.
Drag fold - The result of the plastic deformation of a
rock unit where it has been folded or bent back on itself.
Drawpoint - An underground opening at the bottom of a
stope through which broken ore from the stope is extracted.
Drift - A horizontal underground opening that follows
along the length of a vein or rock formation as opposed to a
crosscut which crosses the rock formation.
Drifter - A hydraulic rock drill used to drill
small-diameter holes for blasting or for installing rock bolts.
Drill-indicated reserves - The size and quality of a
potential orebody as suggested by widely spaced drillholes; more
work is required before reserves can be classified as probable
Dry - A building where the miner changes into working
Due diligence - The degree of care and caution required
before making a decision; loosely, a financial and technical
investigation to determine whether an investment is sound.
Dump - A pile of broken rock or ore on surface.
Dyke - A long and relatively thin body of igneous rock
that, while in the molten state, intruded a fissure in older
Electrolysis - An electric current
is passed through a solution containing dissolved metals,
causing the metals to be deposited onto a cathode.
Electrolytic refining - The process of purifying metal
ingots that are suspended as anodes in an electrolytic bath,
alternated with refined sheets of the same metal which act as
starters or cathodes.
EM survey - A geophysical survey method which measures
the electromagnetic properties of rocks.
En echelon - Roughly parallel but staggered structures.
Enriched uranium - Uranium in which the 235U isotope
concentration has been increased to greater than the 0.711
percent 235U (by weight) present in natural uranium.
Enrichment feed deliveries - Uranium that is shipped under
contract to a supplier of enrichment services for use in
preparing enriched uranium product to a specified 235U
concentration and that ultimately will be used as fuel in a
Enrichment services - (See Separative Work Units).
Environmental impact study - A written report, compiled
prior to a production decision, that examines the effects
proposed mining activities will have on the natural
Epigenetic - Orebodies formed by hydrothermal fluids and
gases that were introduced into the host rocks from elsewhere,
filling cavities in the host rock.
Epithermal deposit - A mineral deposit consisting of
veins and replacement bodies, usually in volcanic or sedimentary
rocks, containing precious metals or, more rarely, base metals.
Equity financing - The provision of funds by buying
Era - A large division of geologic time - the Precambrian
era, for example.
Erosion - The breaking down and subsequent removal of
either rock or surface material by wind, rain, wave action,
freezing and thawing and other processes.
Erratic - Either a piece of visible gold or a large
Escrowed shares - Shares deposited in trust pending
fulfilment of certain conditions, and not ordinarily available
to trading until released.
Ex-dividend - On stocks selling "ex-dividend",
the seller retains the right to a pending dividend payment.
Exploration - Prospecting, sampling, mapping, diamond
drilling and other work involved in searching for ore.
Exploration drilling - Drilling done in search of new
mineral deposits, on extensions of known ore deposits, or at the
location of a discovery up to the time when the company decides
that sufficient ore reserves are present to justify commercial
exploitation. Assessment drilling is reported as exploration
Fabricated fuel - Fuel assemblies
composed of an array of fuel rods loaded with pellets of
enriched uranium dioxide.
Foreign purchase - A uranium purchase of foreign-origin
uranium from a firm located outside of the United States.
Foreign sale - A uranium sale to a firm located outside the
Forward costs (uranium) - The operating and capital costs
that will be incurred in any future production of uranium from
in-place reserves. Included are costs for labor, materials,
power and fuel, royalties, payroll taxes, insurance, and general
and administrative costs that are dependent upon the quantity of
production and, thus, applicable as variable costs of
production. Excluded from forward costs are prior expenditures,
if any, incurred for property acquisition, exploration, mine
development, and mill construction, as well as income taxes,
profit, and the cost of money. Note: By use of forward costing,
estimates of reserves for ore deposits in differing geological
settings can be aggregated and reported as the maximum amount
that can theoretically be extracted to recover the specified
costs of uranium oxide production under the listed forward cost
Face - The end of a drift, crosscut
or stope in which work is taking place.
Fault - A break in the Earth's crust caused by tectonic
forces which have moved the rock on one side with respect to the
Feldspar - A group of common rock-forming minerals that
includes microcline, orthoclase, plagioclase and others.
Felsic - Term used to describe light-colored rocks
containing feldspar, feldspathoids and silica.
Ferrous - Containing iron.
Fine gold - Fineness is the proportion of pure gold or
silver in jewelry or bullion expressed in parts per thousand.
Thus, 925 fine gold indicates 925 parts out of 1,000, or 92.5%
is pure gold.
Fissure - An extensive crack, break or fracture in rocks.
Fixed Assets - Possessions such as buildings, machinery
and land which, as opposed to current assets, are unlikely to be
converted into cash during the normal business cycle.
Float - Pieces of rock that have been broken off and
moved from their original location by natural forces such as
frost or glacial action.
Flotation - A milling process in which valuable mineral
particles are induced to become attached to bubbles and float as
Flowsheet - An illustration showing the sequence of
operations, step by step, by which ore is treated in a milling,
concentration or smelting process.
Flow-through shares - Shares in an exploration company
that allow the tax deduction or credits for mineral exploration
to be passed to the investor.
Flux - A chemical substance that reacts with gangue
minerals to form slags, which are liquid at furnace temperature
and low enough in density to float on the molten bath of metal
Fluxgate magnetometer - An instrument used in geophysics
to measure total magnetic field.
Fold - Any bending or wrinkling of rock strata.
Footwall - The rock on the underside of a vein or ore
Forward contract - The sale or purchase of a commodity
for delivery at a specified future date.
Fracture - A break in the rock, the opening of which
allows mineral-bearing solutions to enter. A
"cross-fracture" is a minor break extending at
more-or-less right angles to the direction of the principal
Free milling - Ores of gold or silver from which the
precious metals can be recovered by concentrating methods
without resorting to pressure leaching or other chemical
Gabbro - A dark, coarse-grained
Galena - Lead sulphide, the most common ore mineral of
Gamma - A unit of measurement of magnetic intensity.
Gangue - The worthless minerals in an ore deposit.
Geiger counter - An instrument used to measure the
radioactivity that emanates from certain minerals by means of a
Geochemistry - The study of the chemical properties of
Geology - The science concerned with the study of the
rocks which compose the Earth.
Geophysics - The study of the physical properties of
rocks and minerals.
Geophysical survey - A scientific method of prospecting
that measures the physical properties of rock formations. Common
properties investigated include magnetism, specific gravity,
electrical conductivity and radioactivity.
Geothermal - Pertains to the heat of the Earth's
Glacial drift - Sedimentary material that has been
transported by glaciers.
Glacial striations - Lines or scratches on a smooth rock
surface caused by glacial abrasion.
Glory hole - An open pit from which ore is extracted,
especially where broken ore is passed to underground workings
before being hoisted.
Gneiss - A layered or banded crystalline metamorphic
rock, the grains of which are aligned or elongated into a
roughly parallel arrangement.
Gold loan - A form of debt financing whereby a potential
gold producer borrows gold from a lending institution, sells the
gold on the open market, uses the cash for mine development,
then pays back the gold from actual mine production.
Gossan - The rust-colored capping or staining of a
mineral deposit, generally formed by the oxidation or alteration
of iron sulphides.
Gouge - Fine, putty-like material composed of ground-up
rock found along a fault.
Grab sample - A sample from a rock outcrop that is
assayed to determine if valuable elements are contained in the
rock. A grab sample is not intended to be representative of the
deposit, and usually the best-looking material is selected.
Graben - A downfaulted block of rock.
Granite - A coarse-grained intrusive igneous rock
consisting of quartz, feldspar and mica.
Gravity meter, gravimeter - An instrument for measuring
the gravitational attraction of the earth; gravitational
attraction varies with the density of the rocks in the vicinity.
Greenstone belt - An area underlain by metamorphosed
volcanic and sedimentary rocks, usually in a continental shield.
Grizzly (or mantle) - A grating, usually constructed of
steel rails, placed over the top of a chute or ore pass for the
purpose of stopping large pieces of rock or ore that may hang up
in the pass.
Gross value - The theoretical value of ore determined
simply by applying the assay of metal or metals and the current
market price. It must be used only with caution and severe
Gross value royalty - A share of gross revenue from the
sale of minerals from a mine.
Grouting - The process of sealing off a water flow in
rocks by forcing a thin slurry of cement or other chemicals into
the crevices; usually done through a diamond drill hole.
Grubstake - Finances or supplies of food, etc., furnished
to a prospector in return for an interest in any discoveries
Guides - The timber rails installed along the walls of a
shaft for steadying, or guiding, the cage or conveyance.
Gypsum - A sedimentary rock consisting of hydrated
Gyratory crusher - A machine that crushes ore between an
eccentrically mounted crushing cone and a fixed crushing throat.
Typically has a higher capacity than a jaw crusher.
Halite - Rock salt.
Hangingwall - The rock on the upper side of a vein or ore
Head grade - The average grade of ore fed into a
Heap leaching - A process whereby valuable metals are leached from a heap, or pad, of
crushed ore by leaching solutions percolating down through the
heap and collected from a sloping, impermeable liner below the
Heap leach solutions - The separation, or dissolving-out,
from mined rock of the soluble uranium constituents by the
natural action of percolating a prepared chemical solution
through mounded (heaped) rock material. The mounded material
usually contains low grade mineralized material and/or waste
rock produced from open-pit or underground mines. The solutions
are collected after percolation is completed and processed to
recover the valued components.
Hedging - Taking a buy or sell position in a futures
market opposite to a position held in the cash market to
minimize the risk of financial loss from an adverse price
Hematite - An oxide of iron, and one of that metal's most
common ore minerals.
High grade - Rich ore. As a verb, it refers to selective
mining of the best ore in a deposit.
High-grader - One who steals rich ore, especially gold,
from a mine.
Hoist - The machine used for raising and lowering the
cage or other conveyance in a shaft.
Holding company - A corporation engaged principally in
holding a controlling interest in one or more other companies.
Hornfels - A fine-grained contact metamorphic rock.
Horse - A mass of waste rock lying within a vein or
Horst - An upfaulted block of rock.
Host rock - The rock surrounding an ore deposit.
Hydrometallurgy - The treatment of ore by wet processes,
such as leaching, resulting in the solution of a metal and its
Hydrothermal - Relating to hot fluids circulating in the
Igneous rocks - Rocks formed by the
solidification of molten material from far below the earth's
Ilmenite - An ore mineral of titanium, being an
Induced polarization - A method of ground geophysical
surveying employing an electrical current to determine
indications of mineralization.
Industrial minerals - Non-metallic, non-fuel minerals
used in the chemical and manufacturing industries. Examples are
asbestos, gypsum, salt, graphite, mica, gravel, building stone
Initial public offering - The first sale of shares to the
public, usually by subscription from a group of investment
In Situ Leach mining (ISL) - The recovery, by chemical
leaching, of the valuable components of an orebody without
physical extraction of the ore from the ground. Also referred to
as “solution mining.”
Institutional investors - Pension funds and mutual funds,
managing money for a large number of individual investors.
Intermediate rock - An igneous rock containing 52% to 66%
Intrusive - A body of igneous rock formed by the
consolidation of magma intruded into other rocks, in contrast to
lavas, which are extruded upon the surface.
Ion exchange - An exchange of ions in a crystal with
irons in a solution. Used as a method for recovering valuable
metals, such as uranium, from solution.
Jaw crusher - A machine in which
rock is broken by the action of steel plates.
Jig - A piece of milling equipment used to concentrate
ore on a screen submerged in water, either by the reciprocating
motion of the screen or by the pulsation of water through it.
Kimberlite - A variety of
peridotite; the most common host rock of diamonds.
Lagging - Planks or small timbers
placed between steel ribs along the roof of a stope or drift to
prevent rocks from falling, rather than to support the main
weight of the overlying rocks.
Lamprophyre - An igneous rock, composed of dark minerals,
that occurs in dykes; sometimes contains diamonds.
Laterite - A residual soil, ususally found in tropical
countries, out of which the silica has been leached. May form
orebodies of iron, nickel, bauxite and manganese.
Launder - A chute or trough for conveying pulp, water or
powdered ore in a mill.
Lava - A general name for the molten rock ejected by
Leachable - Extractable by chemical solvents.
Leaching - A chemical process for the extraction of
valuable minerals from ore; also, a natural process by which
ground waters dissolve minerals, thus leaving the rock with a
smaller proportion of some of the minerals than it contained
Lens - Generally used to describe a body of ore that is
thick in the middle and tapers towards the ends.
Lenticular - A deposit having roughly the form of a
double convex lens.
Level - The horizontal openings on a working horizon in a
mine; it is customary to work mines from a shaft, establishing
levels at regular intervals, generally about 50 metres or more
Lignite - A soft, low-rank, brownish-black coal.
Limestone - A bedded, sedimentary deposit consisting
chiefly of calcium carbonate.
Limit order - An order made by a client to a broker to
buy or sell shares at a specified price or better.
Limonite - A brown, hydrous iron oxide.
Line cutting - Straight clearings through the bush to
permit sightings for geophysical and other surveys.
Lode - A mineral deposit in solid rock.
Logging - The process of recording geological
observations of drill core either on paper or on computer disk.
London fix - The twice-daily bidding session held by five
dealing companies to set the gold price. There are also daily
London fixes to set the prices of other precious metals.
London Metals Exchange - A major bidding market for base
metals, which operates daily in London.
Long position - Securities owned outright or carried on
Long-term contract - One or more deliveries to occur
after a year following contract execution.
Long ton - 2,240 lbs. avoirdupois (compared with a short
ton, which is 2,000 lbs.).
- Igneous rocks composed mostly of dark, iron- and
Magma - The molten material deep in the Earth from which
rocks are formed.
Magmatic segregation - An ore-forming process whereby
valuable minerals are concentrated by settling out of a cooling
Magnetic gradient survey - A geophysical survey using a
pair of magnetometers a fixed distance apart, to measure the
difference in the magnetic field with height above the ground.
Magnetic separation - A process in which a magnetically
susceptible mineral is separated from gangue minerals by
applying a strong magnetic field; ores of iron are commonly
treated in this way.
Magnetic susceptibility - A measure of the degree to
which a rock is attracted to a magnet.
Magnetic survey - A geophysical survey that measures the
intensity of the Earth's magnetic field.
Magnetite - Black, magnetic iron ore, an iron oxide.
Magnetometer - An instrument used to measure the magnetic
attraction of underlying rocks.
Map-staking - A form of claim-staking practised in some
jurisdictions whereby claims are staked by drawing lines around
the claim on claim maps at a government office.
Marble - A metamorphic rock derived from the
recrystallization of limestone under intense heat and pressure.
Margin - Cash deposited with a broker as partial payment
of the purchase price for any type of listed stock. The stock is
held by the broker as security for the loan.
Marginal deposit - An orebody of minimal profitability.
Market order - An order to buy or sell at the best price
available. In absence of any specified price or limit, an order
is considered to be "at the market".
Matte - A product of a smelter, containing metal and some
sulphur, which must be refined further to obtain pure metal.
Metallurgical coal - Coal used to make steel.
Metallurgy - The study of extracting metals from their
Metamorphic rocks - Rocks which have undergone a change
in texture or composition as the result of heat and/or pressure.
Metamorphism - The process by which the form or structure
of rocks is changed by heat and pressure.
Migmatite - Rock consisting of thin, alternating layers
of granite and schist.
Mill - A plant in which ore is treated and metals are
recovered or prepared for smelting; also a revolving drum used
for the grinding of ores in preparation for treatment.
Milling ore - Ore that contains sufficient valuable
mineral to be treated by milling process.
Milling of uranium - The processing of
uranium from ore mined by conventional methods, such as
underground or openpit, to separate the uranium from the
undesired material in the ore.
Millivolts - A measure of the voltage of an electric
current, specifically, one-thousandth of a volt.
Minable reserves - Ore reserves that are known to be
extractable using a given mining plan.
Mineral - A naturally occurring homogeneous substance
having definite physical properties and chemical composition
and, if formed under favorable conditions, a definite crystal
Mining MarketWatch - MiningMarketWatch.com is your
ultimate source for mining information.
- Ore or rock that has been broken by blasting.
Muck sample - A representative piece of ore that is taken
from a muck pile and then assayed to determine the grade of the
Nanotesla - The international unit
for measuring magnetic flux density.
National Uranium Resource Evaluation (NURE) - A program
begun by the U.S. Atomic Energy Commission (AEC) in 1974 to make
a comprehensive evaluation of U.S. uranium resources and
continued through 1983 by the AEC's successor agencies, the
Energy Research and Development Administration (ERDA) and the
Depart-ment of Energy (DOE). The NURE program included aerial
radiometric and magnetic surveys, hydrogeochemical and stream
sediment surveys, geologic drilling in selected areas,
geophysical logging of selected boreholes, and geologic studies
to identify and evaluate geologic environments favorable for
Nonconventional plant (uranium) - A facility engineered
and built principally for processing of uraniferous solutions
that are produced during in situ leach mining, from heap
leaching, or in the manufacture of other commodities, and the
recovery, by chemical treatment in the plant’s circuits, of
uranium from the processed solutions.
Nuclear electric power (nuclear power) - Electricity
generated by an electric power plant whose turbines are driven
by steam produced by the heat from the fission of nuclear fuel
in a reactor.
Nuclear reactor - An apparatus in which a nuclear fission
chain reaction can be initiated, controlled, and sustained at a
specific rate. A reactor includes fuel (fissionable material),
moderating material to control the rate of fission, a
heavy-walled pressure vessel to house reactor components,
shielding to protect personnel, a system to conduct heat away
from the reactor, and instrumentation for monitoring and
controlling the reactor’s systems.
Native metal - A metal occurring in nature in pure form,
uncombined with other elements.
Net profit interest - A portion of the profit remaining
after all charges, including taxes and bookkeeping charges, such
as depreciation, have been deducted.
Net smelter return - A share of the net revenues
generated from the sale of metal produced by a mine.
Net worth - The difference between total assets and total
Norite - A coarse-grained igneous rock that is host to
copper/nickel deposits in the Sudbury area of Ontario.
Nugget - A small mass of precious metal, found free in
Odd lot - A block of shares that is
less than a board lot.
Open order - An order to buy or sell stock, which is good
until cancelled by the client.
Open pit - A mine that is entirely on surface. Also
referred to as open-cut or open-cast mine.
Option - An agreement to purchase a property reached
between the property vendor and some other party who wishes to
explore the property further.
Option (on stock) - The right to buy or sell a share at a
set price, regardless of market value.
Optional delivery commitment - A provision to allow the
conditional purchase or sale of a specific quantity of material
in addition to the firm quantity in the contract.
Ore - A mixture of ore minerals and gangue from which at
least one of the metals can be extracted at a profit.
Ore pass - Vertical or inclined passage for the downward
transfer of ore connecting a level with the hoisting shaft or a
Orebody - A natural concentration of valuable material
that can be extracted and sold at a profit.
Ore Reserves - The calculated tonnage and grade of
mineralization which can be extracted profitably; classified as
possible, probable and proven according to the level of
confidence that can be placed in the data.
Oreshoot - The portion, or length, of a vein or other
structure that carries sufficient valuable minerals to be
Organic maturation - The process of turning peat into
Orogeny - A period of mountain-building characterized by
the folding of a portion of the earth's crust.
Outcrop - An exposure of rock or mineral deposit that can
be seen on surface, that is, not covered by soil or water.
Overturned - Where the oldest sedimentary rock beds are
lying on top of a younger beds.
Oxidation - A chemical reaction caused by exposure to
oxygen that results in a change in the chemical composition of a
Person Year - One whole year, or fraction thereof, worked by
an employee, including contracted manpower. It is expressed as a
quotient (to two decimal places) of the time units worked during
a year (hours, weeks, or months) divided by the like total time
units in a year. For example: 80 hours worked is 0.04 (rounded)
of a person year; 8 weeks worked is 0.15 (rounded) of a person
year; 12 months worked is 1.0 person year. Contracted manpower
includes survey crews, drilling crews, consultants, and other
persons who worked under contract to support your firm’s ongoing
Processing of uranium - Uranium-recovery operations at a
mill, in-situ leach plant, byproduct plant, or other type of
Pan - To wash gravel, sand or
crushed rock samples in order to isolate gold or other valuable
metals by their higher density.
Participating interest - A company's interest in a mine,
which entitles it to a certain percentage of profits in return
for putting up an equal percentage of the capital cost of the
Par value - The stated face value of a stock. Par value
shares have no specified face value, but the total amount of
authorized capital is set down in the company's charter.
Patent - The ultimate stage of holding a mineral claim,
after which no more assessment work is necessary because all
mineral rights have been earned.
Pegmatite - A coarse-grained, igneous rock, generally
coarse, but irregular in texture, and similar to a granite in
composition; usually occurs in dykes or veins and sometimes
contains valuable minerals.
Pellet - A marble-sized ball of iron ore fused with clay
for transportation and use in steelmaking.
Pentlandite - Nickel iron sulphide, the most common
Peridotite - An intrusive igneous rock consisting mainly
Phaneritic - A term used to describe the coarse-grained
texture of some igneous rocks.
Picket line - A reference line, marked by pickets or
stakes, established on a property for mapping and survey
Pig iron - Crude iron from a blast furnace.
Pillar - A block of solid ore or other rock left in place
to structurally support the shaft, walls or roof of a mine.
Pitchblende - An important uranium ore mineral. It is
black in color, possesses a characteristic greasy lustre and is
Placer - A deposit of sand and gravel containing valuable
metals such as gold, tin or diamonds.
Plant - A building or group of buildings in which a
process or function is carried out; at a mine site it will
include warehouses, hoisting equipment, compressors, maintenance
shops, offices and the mill or concentrator.
Plate tectonics - A geological theory which postulates
that the Earth's crust is made up of a number of rigid plates
which collide, rub up against and spread out from one another.
Plug - A common name for a small offshoot from a large
body of molten rock.
Plunge - The vertical angle a linear geological feature
makes with the horizontal plane.
Plutonic - Refers to rocks of igneous origin that have
come from great depth.
Point - Unit of value of a stock as quoted by a stock
exchange. May represent one dollar, one cent or one-eighth of a
dollar, depending on the stock exchange.
Polishing pond - The last in a series of settling ponds
through which mill effluent flows before being discharged into
the natural environment.
Pooling shares - See escrowed shares.
Porphyry - Any igneous rock in which relatively large
crystals , called phenocrysts, are set in a fine-grained
Porphyry copper - A deposit of disseminated copper
minerals in or around a large body of intrusive rock.
Portal - The surface entrance to a tunnel or adit.
Portfolio - A list of financial assets.
Possible reserves - Valuable mineralization not sampled
enough to accurately estimate its tonnage and grade, or even
verify its existence. Also called "inferred reserves."
Potash - Potassium compounds mined for fertilizer and for
use in the chemical industry.
Precambrian Shield - The oldest, most stable regions of
the earth's crust, the largest of which is the Canadian Shield.
Preferred shares - Shares of a limited liability company
that rank ahead of common shares, but after bonds, in
distribution of earnings or in claim to the company's assets in
the event of liquidation. They pay a fixed dividend but normally
do not have voting rights, as with common shares.
Price-to-earnings ratio - The current market price of a
stock divided by the company's net earnings per share for the
Primary deposits - Valuable minerals deposited during the
original period or periods of mineralization, as opposed to
those deposited as a result of alteration or weathering.
Private placement - Sale of shares to individuals or
corporations outside the normal market, at a negotiated price.
Often used to raise capital for a junior exploration company.
Pro rata - In proportion, usually to ownership, income or
Probable reserves - Valuable mineralization not sampled
enough to accurately estimate the terms of tonnage and grade.
Also called "indicated reserves."
Profit and loss statement - The income statement of a
company detailing revenues minus total costs to give total
Prospect - A mining property, the value of which has not
been determined by exploration.
Prospectus - A document filed with the appropriate
securities commission detailing the activities and financial
condition of a company seeking funds from the public through the
issuance of shares.
Proton precession magnetometer - A geophysical instrument
which measures magnetic field intensity in terms of vertical
gradient and total field.
Proven reserves - Reserves that have been sampled
extensively by closely spaced diamond drill holes and developed
by underground workings in sufficient detail to render an
accurate estimation of grade and tonnage. Also called
Proxy - A power of attorney given by the shareholder so
that his stock may be voted by his nominee(s) at shareholders'
Pulp - Pulverized or ground ore in solution.
Put - An option to sell a stock at an agreed upon price
within a specified time. The owner can present his put to the
contracting broker at any time within the option period and
compel him to buy the stock.
Pyramiding - The use of increased buying power to
increase ownership arising from price appreciation.
Pyrite - A yellow iron sulphide mineral, normally of
little value. It is sometimes referred to as "fool's
Pyrrhotite - A bronze-colored, magnetic iron sulphide
Quartz - Common rock-forming
mineral consisting of silicon and oxygen.
Quartzite - A metamorphic rock formed by the
transformation of a sandstone by heat and pressure.
Radioactivity - The property of
spontaneously emitting alpha, beta or gamma rays by the decay of
the nuclei of atoms.
Radon survey - A geochemical survey technique which
detects traces of radon gas, a product of radioactivity.
Raise - A vertical or inclined underground working that
has been excavated from the bottom upward.
Rake - The trend of an orebody along the direction of its
Rare earth elements - Relatively scarce minerals such as
niobium and yttrium.
Reaming shell - A component of a string of rods used in
diamond drilling, it is set with diamonds and placed between the
bit and the core barrel to maintain the gauge (or diameter) of
Reclamation - The restoration of a site after mining or
exploration activity is completed. Includes surface contouring,
equipment removal, well plugging, revegetation, etc.
Reconnaissance - A preliminary survey of ground.
Record date - The date by which a shareholder must be
registered on the books of a company in order to receive a
declared dividend, or to vote on company affairs.
Recovery - The percentage of valuable metal in the ore
that is recovered by metallurgical treatment.
Refractory ore - Ore that resists the action of chemical
reagents in the normal treatment processes and which may require
pressure leaching or other means to effect the full recovery of
the valuable minerals.
Regional metamorphism - Metamorphism caused by both the
heat of igneous processes and tectonic pressure.
Replacement ore - Ore formed by a process during which
certain minerals have passed into solution and have been carried
away, while valuable minerals from the solution have been
deposited in the place of those removed.
Reserve Cost Categories of $15, $30, $50, and $100 per Pound
U3O8 - Classification of uranium reserves estimated by using
break-even cutoff grades that are calculated based on
forward-operating costs of less than $15, $30, $50, and $100 per
Resistivity survey - A geophysical technique used to
measure the resistance of a rock formation to an electric
Resource - The calculated amount of material in a mineral
deposit, based on limited drill information.
Restoration - The returning of all affected groundwater
to its premining quality for its premining use by employing the
best practical technology.
Resuing - A method of stoping in narrow-vein deposits
whereby the wallrock on one side of the vein is blasted first
and then the ore.
Reverberatory furnace - A long, flat furnace used to slag
gangue minerals and produce a matte.
Rhyolite - A fine-grained, extrusive igneous rock which
has the same chemical composition as granite.
Rib samples - Ore taken from rib pillars in a mine to
determine metal content.
Rights - In finance, a certified right to purchase
treasury shares in stated quantities, prices and time limits;
usually negotiable at a price which is related to the prices of
the issue represented; also referred to as warrants. Rights and
warrants can be bought and sold prior to their expiry date
because not all shareholders wish to exercise their rights.
Rock - Any natural combination of minerals; part of the
Rockbolting - The act of supporting openings in rock with
steel bolts anchored in holes drilled especially for this
Rockburst - A violent release of energy resulting in the
sudden failure of walls or pillars in a mine, caused by the
weight or pressure of the surrounding rocks.
Rock factor - The number of cubic metres of a particular
rock type required to make up one tonne of the material. One
tonne of a highly siliceous ore may occupy 0.40 cubic metres,
while a tonne of dense sulphide ore may occupy only 0.25 cubic
Rock mechanics - The study of the mechanical properties
of rocks, which includes stress conditions around mine openings
and the ability of rocks and underground structures to withstand
Rod mill - A rotating steel cylinder that uses steel rods
as a means of grinding ore.
Room-and-pillar mining - A method of mining
flat-lying ore deposits in which the mined-out area, or rooms,
are separated by pillars of approximately the same size.
Rotary drill - A machine that drills holes by rotating a
rigid, tubular string of drill rods to which is attached a bit.
Commonly used for drilling large-diameter blastholes in open-pit
Royalty - An amount of money paid at regular intervals by
the lessee or operator of an exploration or mining property to
the owner of the ground. Generally based on a certain amount per
tonne or a percentage of the total production or profits. Also,
the fee paid for the right to use a patented process.
Run-of-mine - A term used loosely to describe ore of
Salting - The act of introducing
metals or minerals into a deposit or samples, resulting in false
assays. Done either by accident or with the intent of defrauding
Sample - A small portion of rock or a mineral deposit
taken so that the metal content can be determined by assaying.
Sampling - Selecting a fractional but representative part
of a mineral deposit for analysis.
Sandstone - A sedimentary rock consisting of grains of
sand cemented together.
Scaling - The act of removing loose slabs of rock from
the back and walls of an underground opening, usually done with
a hand-held scaling bar or with a boom-mounted scaling hammer.
Scarp - An escarpment, cliff or steep slope along the
margin of a plateau, mesa or terrace.
Schist - A foliated metamorphic rock the grains of which
have a roughly parallel arrangement; generally developed by
Scintillation counter - An instrument used to detect and
measure radioactivity by detecting gamma rays; more sensitive
than a geiger counter.
Secondary enrichment - Enrichment of a vein or mineral
deposit by minerals that have been taken into solution from one
part of the vein or adjacent rocks and redeposited in another.
Sedimentary rocks - Secondary rocks formed from material
derived from other rocks and laid down under water. Examples are
limestone, shale and sandstone.
Seismic prospecting - A geophysical method of
prospecting, utilizing knowledge of the speed of reflected sound
waves in rock.
Self-potential - A technique, used in geophysical
prospecting, which recognizes and measures the minute electric
currents generated by sulphide deposits.
Semi-autogenous grinding (SAG) - A method of grinding
rock into fine powder whereby the grinding media consist of
larger chunks of rocks and steel balls.
Separative Work Units (SWU) - The standard measure of
enrichment services. The effort expended in separating a mass F
of feed of assay xf into a mass P of product assay xp and waste
of mass W and assay xw is expressed in terms of the number of
separative work units needed, given by the expression SWU =
WV(xw) + PV(xp) - FV(xf), where V(x) is the "value function,"
defined as V(x) = (1 - 2x) ln((1 - x)/x).
Serpentine - A greenish, metamorphic mineral consisting
of magnesium silicate.
Shaft - A vertical or inclined excavation in rock for the
purpose of providing access to an orebody. Usually equipped with
a hoist at the top, which lowers and raises a conveyance for
handling workers and materials.
Shale - Sedimentary rock formed by the consolidation of
mud or silt.
Shear or shearing - The deformation of rocks by lateral
movement along innumerable parallel planes, generally resulting
from pressure and producing such metamorphic structures as
cleavage and schistosity.
Shear zone - A zone in which shearing has occurred on a
Sheave wheel - A large, grooved wheel in the top of a
headframe over which the hoisting rope passes.
Shoot - A concentration of mineral values; that part of a
vein or zone carrying values of ore grade.
Short selling - The borrowing of stock from a broker in
order to sell it in the hope that it may be purchased at a lower
price later on.
Short ton - 2,000 lbs. avoirdupois.
Shrinkage stoping - A stoping method which uses part of
the broken ore as a working platform and as support for the
walls of the stope.
Siderite - Iron carbonate, which when pure, contains
48.2% iron; must be roasted to drive off carbon dioxide before
it can be used in a blast furnace. Roasted product is called
Silica - Silicon dioxide. Quartz is a common example.
Siliceous - A rock containing an abundance of quartz.
Sill - An intrusive sheet of igneous rock of roughly
uniform thickness that has been forced between the bedding
planes of existing rock.
Silt - Muddy deposits of fine sediment usually found on
the bottoms of lakes.
Sinter - Fine particles of iron ore that have been
treated by heat to produce blast furnace feed.
Skarn - Name for the metamorphic rocks surrounding an
igneous intrusive where it comes in contact with a limestone or
Skip - A self-dumping bucket used in a shaft for hoisting
ore or rock.
Slag - The vitreous mass separated from the fused metals
in the smelting process.
Slash - The process of blasting rock from the side of an
underground opening to widen the opening.
Slate - A metamorphic rock; the metamorphic equivalent of
Slickenside - The striated, polished surface of a fault
caused by one wall rubbing against the other.
Sludge - Rock cuttings from a diamond drill hole,
sometimes used for assaying.
Sodium cyanide - A chemical used in the milling of gold
ores to dissolve gold and silver.
Solvent extraction-electrowinning (SX-EW) - A
metallurgical technique, so far applied only to copper ores, in
which metal is dissolved from the rock by organic solvents and
recovered from solution by electrolysis.
Spelter - The zinc of commerce, more or less impure, cast
from molten metal into slabs or ingots.
Sphalerite - A zinc sulphide mineral; the most common ore
mineral of zinc.
Split - The shareholder-approved division of a company's
outstanding common shares into a larger number of new common
Spot contract - A one-time delivery of the entire
contract to occur within one year of contract execution.
Spot market - Buying and selling of uranium for immediate
or very near-term delivery. It typically involves transactions
for delivery of up to 500,000 pounds U3O8 within a year of
Spot-market price - A transaction price concluded “on the
spot,” that is, on a one-time, prompt basis. The transaction
usually involves only one specific quantity of product. This
contrasts with a term-contract sale price, which obligates the
seller to deliver a product at an agreed frequency and price
over an extended period.
Station - An enlargement of a shaft made for the storage
and handling of equipment and for driving drifts at that
Step-out drilling - Holes drilled to intersect a
mineralization horizon or structure along strike or down dip.
Stock exchange - An organized market concerned with the
buying and selling of common and preferred shares and warrants
by stockbrokers who own seats on the exchange and meet
Stockpile - Broken ore heaped on surface, pending
treatment or shipment.
Stope - An excavation in a mine from which ore is, or has
Stop-loss order - An arrangement whereby a client gives
his broker instructions to sell a stock if and when its price
drops to a specified figure on the market.
Stratigraphy - Strictly, the description of bedded rock
sequences; used loosely, the sequence of bedded rocks in a
Streak - A diagnostic characteristic of minerals, where
scratching a sample on a piece of unglazed porcelain leaves
powder of a characteristic color.
Street certificate - A certificate representing ownership
in a specified number of shares that is registered in the name
of some previous owner who has endorsed the certificate so that
it may be transferred to a new owner without referral to
Striations - Prominent parallel scratches left on bedrock
by advancing glaciers.
Strike - The direction, or bearing from true north, of a
vein or rock formation measure
on a horizontal surface.
Stringer - A narrow vein or irregular filament of a
mineral or minerals traversing a rock mass.
Strip - To remove the overburden or waste rock overlying
an orebody in preparation for mining by open pit methods.
Stripping ratio - The ratio of tonnes removed as waste
relative to the number of tonnes of ore removed from an open-pit
Strip mine - An open-pit mine, usually a coal mine,
operated by removing overburden, excavating the coal seam, then
returning the overburden.
Sub-bituminous - A black coal, intermediate between
lignite and bituminous.
Sublevel - A level or working horizon in a mine between
main working levels.
Subsidiary company - A company in which the majority of
shares (a controlling position) is held by another company.
Sulphide - A compound of sulphur and some other element.
Sulphide dust explosions - An underground mining hazard
involving the spontaneous combustion of airborne dust containing
Sulphur dioxide - A gas liberated during the smelting of
most sulphide ores; either converted into sulphuric acid or
released into the atmosphere in the form of a gas.
Sump - An underground excavation where water accumulates
before being pumped to surface.
Sustainable development - Industrial development that
does not detract from the potential of the natural environment
to provide benefits to future generations.
Syenite - An intrusive igneous rock composed chiefly of
Sylvite - potassium chloride, the principal ore of
potassium mined for fertilizer manufacturing.
Syncline - A down-arching fold in bedded rocks.
Syngenetic - A term used to describe when mineralization
in a deposit was formed relative to the host rocks in which it
is found. In this case, the mineralization was formed at the
same time as the host rocks. (The opposite is epigenetic.)
Taconite - A highly abrasive iron
Tailings - Material rejected from a mill after most of
the recoverable valuable minerals have been extracted.
Tailings pond - A low-lying depression used to confine
tailings, the prime function of which is to allow enough time
for heavy metals to settle out or for cyanide to be destroyed
before water is discharged into the local watershed.
Talus - A heap of broken, coarse rock found at the base
of a cliff or mountain.
Telluride - A chemical compound consisting of the element
tellurium and another element, often gold or silver.
Thermal coal - Coal burned to generate the steam that
drives turbines to generate electricity.
Thickener - A large, round tank used in milling
operations to separate solids from liquids; clear fluid
overflows from the tank and rock particles sink to the bottom.
Tonnes-per-vertical-metre - Common unit used to describe
the amount of ore in a deposit; ore length is multiplied by the
width and divided by the appropriate rock factor to give the
amount of ore for each vertical metre of depth.
Trading floor - the area of a stock exchange building
where shares are bought and sold.
Trading post - An area on the trading floor of a stock
exchange where current stock prices are listed and where the
floor traders (representatives of brokerage firms) meet to buy
or sell the stocks listed at that particular post.
Tram - To haul cars of ore or waste in a mine.
Treasury shares - The unissued shares in a company's
Trench - A long, narrow excavation dug through
overburden, or blasted out of rock, to expose a vein or ore
Trend - The direction, in the horizontal plane, of a
linear geological feature, such as an ore zone, measured from
Tube mill - An apparatus consisting of a revolving
cylinder about half-filled with steel rods or balls and into
which crushed ore is fed for fine grinding.
Tuff - Rock composed of fine volcanic ash.
Tunnel - A horizontal underground opening, open to the
atmosphere at both ends.
Tunnel-boring-machine - A machine used to excavate a
tunnel through soil or rock by mechanical means as opposed to
drilling and blasting.
Umpire sample or assay - An assay
made by a third party to provide a basis for settling disputes
between buyers and sellers of ore.
Uncut value - The actual assay value of a core sample as
opposed to a cut value which has been reduced by some arbitrary
Underwrite - A firm commitment made by a broker or other
financial institution to purchase a block of shares at a
Unfilled requirements -Requirements not covered by usage
of inventory or supply contracts in existence as of January 1 of
the survey year.
Uraninite - A uranium mineral with a high uranium oxide
content. Frequently found in pegmatite dykes.
- A heavy, naturally radioactive, metallic element (atomic
number 92). Its two principally occurring isotopes are 235U and
238U. The isotope 235U is indispensable to the nuclearindustry
because it is the only isotope existing in nature to any
appreciable extent that is fissionable by thermal neutrons. The
isotope 238U is also important because it absorbs neutrons to
produce a radioactive isotope that subsequently decays to the
isotope 239Pu, which also is fissionable by thermal neutrons.
Uranium concentrate - A yellow or brown powder obtained
by the milling of uranium ore, processing of in situ leach
mining solutions, or as a byproduct of phosphoric acid
Uranium deposit - A discrete concentration of uranium
mineralization that is of possible economic interest.
Uranium endowment - The uranium that is estimated to
occur in rock with a grade of at least 0.01 percent U3O8. The
estimate of the uranium endowment is made before consideration
of economic availability and any associated uranium resources.
Uranium hexafluoride (UF6) - A white solid obtained by
chemical treatment of U3O8 and which forms a vapor at
temperatures above 56 degrees Centigrade. UF6 is the form of
uranium required for the enrichment process.
Uranium ore - Rock containing uranium mineralization in
concentrations that can be mined economically, (typically 1 to 4
pounds of U3O8 per ton or 0.05 to 0.20 percent U3O8).
Uranium oxide - Uranium concentrate or yellowcake.
Abbreviated as U3O8.
Uranium property - A specific tract of land with known
uranium reserves that could be developed for mining.
Uranium reserves - Estimated quantities of uranium in
known mineral deposits of such size, grade, and configuration
that the uranium could be recovered at or below a specified
production cost with currently proven mining and processing
technology and under current law and regulations. Reserves are
based on direct radiometric and chemical measurements of drill
hole and other types of sampling of the deposits. Mineral grades
and thickness, spatial relationships, depths below the surface,
mining and reclamation methods, distances to milling facilities,
and amenability of ores to processing are considered in the
evaluation. The amounts of uranium in ore that could be
exploited within the chosen forward-cost levels are estimated
utilizing available sampling, engineering, geologic, and
economic data in accordance with conventional engineering
Uranium resources categories - Three categories of uranium
resources are used to reflect differing levels of confidence in
the resources reported. Reasonably assured resources (RAR),
estimated additional resources (EAR), and speculative
resources (SR) are described below....
Reasonably assured resources (RAR) - The uranium that occurs
in known mineral deposits of such size, grade, and configuration
that it could be recovered within the given production cost
ranges, with currently proven mining and processing technology.
Estimates of tonnage and grade are based on specific sample data
and measurements of the deposits and on knowledge of deposit
characteristics. RAR correspond to DOE's uranium reserves
Estimated additional resources (EAR) - The uranium in
addition to RAR that is expected to occur, mostly on the basis
of direct geological evidence, in extensions of well-explored
deposits, little explored deposits, and undiscovered deposits
believed to exist along well-defined geological trends with
known deposits, such that the uranium can subsequently be
recovered within the given cost ranges. Estimates of tonnage and
grade are based on available sampling data and on knowledge of
the deposit characteristics, as determined in the best-known
parts of the deposit or in similar deposits. EAR correspond to
DOE's probable potential resources category.
Speculative resources (SR) - Uranium in addition to EAR that
is thought to exist, mostly on the basis of indirect evidence
and geological extrapolations, in deposits discoverable with
existing exploration techniques. The locations of deposits in
this category can generally be specified only as being somewhere
within given regions or geological trends. The estimates in this
category are less reliable than estimates of RAR and EAR. The
category of SR corresponds to DOE's possible potential resources
plus speculative potential resources categories combined.
Usage Agreement - Contracts held by enrichment customers
that allow feed material to be stored at the enrichment plant
site in advance of need.
Vein - A fissure, fault or crack in
a rock filled by minerals that have travelled upwards from some
Vendor - A seller. In the case of mining companies, the
consideration paid for properties purchased is often a block of
treasury shares. These shares are termed vendor shares and are
normally pooled or escrowed.
Visible gold - Native gold which is discernible, in a
hand specimen, to the unaided eye.
Volcanic rocks - Igneous rocks formed from
magma that has flowed out or has been violently ejected from a
Volcanogenic - A term used to describe the volcanic
origin of mineralization.
Voting right - The stockholder's right to vote in the
affairs of the company. Most common shares have one vote each.
Preferred stock usually has the right to vote when preferred
dividends are in default.
Vug - A small cavity in a rock, frequently lined with
well-formed crystals. Amethyst commonly forms in these cavities.
Wall rocks - Rock units on either
side of an orebody. The hangingwall and footwall rocks of an
Warrant - See Rights.
Waste - Unmineralized, or sometimes mineralized, rock
that is not minable at a profit.
Wedge - A technique of directing a diamond drill hole in
a desired direction away from its current orientation.
Winze - An internal shaft.
Witness post - A claim post placed on a claim line when
it cannot be placed in the corner of a claim because of water or
Working capital - The liquid resources a company has to
meet day-to-day expenses of operation; defined as the excess of
current assets over current liabilities.
Writeoffs - Amounts deducted from a company's reported
profit for depreciation or preproduction costs. Writeoffs are
not an out-of-pocket expense, but reduce the amount of taxable
Xenolith - A fragment of country
rock enclosed in an intrusive rock.
Yellowcake - A natural uranium concentrate that takes its
name from its color and texture. Yellowcake typically contains
70 to 90 percent U3O8 by weight. It is used as feedstock for
uranium fuel enrichment and fuel pellet fabrication. Yellow cake
is also known as "uranium oxide" (see uranium oxide).
Yield - The current annual dividend
rate expressed as a percentage of the current market price of
Zone - An area of distinct
Zone of oxidation - The upper portion of an orebody that
has been oxidized.
©2005 - 2007 Uranium