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Acidic precipitation – Snow and rain that has a low pH, caused by sulfur dioxide and nitric oxide gases from industrial activity released into the atmosphere.

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 sulfide 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, radioactivity, etc.

Alloy – A compound of two or more metals.

Alluvium – Relatively recent deposits of sedimentary material laid down in riverbeds, 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 than metamorphism.

Amorphous – A term applied to rocks or minerals that possess no definite crystal structure or form, such as amorphous carbon.

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.

AMT – Audio-range magneto-telluric. A type of geophysical survey which uses frequencies generally within the range of human hearing, except as electromagnetic (EM) waves rather than audible mechanical sound waves. AMT is able to detect narrow mineralized bodies or veins of sulfide mineralization at significant depths, from 500 to 5,000 feet below the surface. There are two types of AMT: CSAMT and NSAMT.

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 matter.

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 coal.

Assay – A chemical test performed on a sample of ores or minerals to determine the amount of valuable metals contained.

Assay foot (meter, inch, centimeter) – The assay value multiplied by the number of feet, meters, inches, centimeters 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, which must be performed each year in order to retain legal control of mining claims.

Audio-range magneto-telluric – see AMT

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 underground opening.

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 minerals.

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 that may be covered by younger rocks.

Base camp – Center of operations from which exploration activity is conducted.

Base metal – Any non-precious metal (e.g. 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 very low phosphorus content.

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 rocks.

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 sulfide).

Black smoker – Volcanic vent found in areas of active ocean floor spreading, through which sulfide-laden fluids escape.

Blaster – A mine employee responsible for loading, priming and detonating blast holes.

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.

Blast hole – A drill hole in a mine that is filled with explosives in order to blast loose a quantity of rock.

Bleb – In petrology, a small usually rounded (but sometimes crystalline) inclusion of one material in another.

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 – A mining method suited for ore bodies that have a barren or low-grade capping too thick to strip away from the surface. In development, evenly spaced crosscuts are made below the bottom of the ore block to be caved, from which raises are driven up to the ore. The entire ore block is undercut so that it will begin caving into the raises. The weight of the capping and ore provides the force to crush and move the ore downward, where it is drawn from the raises beneath, trammed to the shaft or decline, and hoisted to the surface. As broken ore is removed, the capping will gradually descend until broken fragments of it coming from the raises indicate that all of the ore has been withdrawn. The surface over the worked-out mine is a gigantic collapse feature, not as deep as the height of withdrawn, because of the “swell factor” of the broken capping, but considerably larger in diameter than the area actually caved underground.

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 access.

Break – Loosely used to describe a large-scale regional shear zone or structural fault.

Breast – A working face in a mine, usually restricted to a stope.

Breccia Pipe, Solution-Collapse Type – Uraninite and associated sulfide, arsenide, sulfate, and arsenic-sulfosalt minerals including minerals of uranium, copper, molybdenum, zinc, lead, silver, gold, nickel, cobalt, selenium, gallium, germanium, cadmium, cesium, chromium, mercury, arsenic, strontium, vanadium, barium and antimony, as disseminated replacements and minor fracture fillings in distinct bodies in near-vertical cylindrical solution-collapse breccia pipes, 30-175 m in diameter and 1,000 m in vertical height. Over 90 minerals species have been reported from these deposits and they host the highest grade uranium mine in the United States and second highest in the world. Pipes located in flat-lying upper Paleozoic and Triassic rocks restricted to the Grand Canyon region in the southwestern part of the Colorado Plateau. [more info] Wikipedia Article on Arizona Breccia Pipe Uranium Mineralization

Breccia Pipe, Explosive-Fluidized Porphyry Copper Type – An explosive-fluidized porphry copper related geologic structure. [more info]

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 drill hole to lend support in blocky ground.

Cage – The conveyance used to transport men and equipment between the surface and the mine levels.

Calcine – that is ready for smelting (i.e. the sulfur has been driven off by oxidation).

Call – An option to buy shares at a specified price. The opposite of a “put”.

Caldera – A large, basin-shaped volcanic depression, more or less circular or cirquelike in form, the diameter of which is many times greater than that of the included vent or vents, no matter what the steepness of the walls or form of the floor.

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 manway.

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 coconut shells.

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 outlay.

Cathode – A rectangular plate of metal, produced by electrolytic refining, which is melted into commercial shapes such as wire bars, billets, ingots, etc.

Cesium magnetometer – A geophysical instrument that measures magnetic field strength in terms of vertical gradient and total field.

Chalcocite – A sulfide mineral of copper common in the zone of secondary enrichment.

Chalcopyrite – A sulfide 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 aluminum silicates.

Cleavage – The tendency of a mineral to split along crystallographic planes.

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.

Coal Mining – There are some significant differences between the processes used in the mining of coal, and those used for mineral mining. For a good introduction to coal and coal mining we highly recommend this report from the Colorado Geological Survey.

Coalification – The metamorphic processes of forming coal.

Collar – The term applied to the timbering or concrete around the mouth of a shaft; also used to describe the top of a mill hole.

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 valuable metals.

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. In the case of Uranium – The product resulting from the milling of uranium ore, typically containing 80 – 90% U3O8, which is also referred to as “yellowcake”. It is usually measured in terms of pounds of contained U3O8 or kilograms of contained U.

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.

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.

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.

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.

Controlled source audio-range magneto-telluric – see CSAMT

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 – 1.)In copper smelting, a furnace used to separate copper metal from matte.
2.)The operator of a facility licensed to receive, store and transform U3O8 into another chemical form suitable for subsequent processing.

Copper – A malleable, ductile, metallic element having a characteristic reddish-brown color: used in large quantities as an electrical conductor and in the manufacture of alloys, as brass and bronze. Symbol: Cu; atomic weight: 63.54; atomic number: 29; specific gravity: 8.92 at 20°C.

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.

CSAMT – Controlled source AMT. A type of AMT survey wherein the EM waves are generated by an electric generator, generally 3 to 5 miles distant from and at right angles to the survey line. see also NSAMT

Cum-dividend – Buyer entitled to pending dividend payment.

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 that processes concentrates from independent mines. Concentrates may be purchased or the smelter may be contracted to do the processing for the independent company.

Cut-and-fill stoping – A mining method similar to shrinkage stoping, except that as each cut of ore is removed, a layer of waste is placed in the the stope to support the stope walls and to serve as a platform for miners and their equipment. All ore is taken from the stopes as it is mined, through tightly timbered raises up through the fill, called ore chutes. Broken waste rock is commonly used for fill and usually comes from development headings elsewhere in the mine. This practice makes it possible to dispose of waste rock underground without the expense of hoisting it to the surface for dumping. Cut and fill stoping methods are used where one or both walls may be weak, so that they would collapse into the stope to mix with broken ore if not carefully supported.

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 Bond

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.

Depleted uranium tails – Uranium where the U-235 content is below the naturally occurring 0.71% as the result of the enrichment process.

Depletion – An accounting device, used primarily in tax computations. It recognizes the consumption of an ore deposit, a mine’s principal asset.

Deposits – A concentration of mineral matter or sediment in a layer, vein, or pocket: iron ore deposits; rich deposits of oil and natural gas.

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 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. [more info]

diamond core drill rig trucktrack mountedDiamond core drill (aka Core drill) – is a drill designed to remove a cylinder of rock material. The rock material is left inside the drill bit and core barrel is referred to as ‘core.’ And it is retrieved by a wire line comonly every 10 feet. Since the drill bit is (generally) impregnated with diamonds for cutting ground by abrasion, this method is also called diamond core drilling. [Exploration diamond drilling, Wikipedia]

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 strike.

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.

Dipole-dipole induced polarization – A linear electrical induced polarization geophysical method in which measurements are collected along a straight line using an input of current electrode and a receiver dipole electrode—known as a dipole-dipole array.

Directional drilling – A method of drilling involving the use of stabilizers and wedges to direct the orientation of the hole.

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 rock.

Dividend – Cash or stock awarded to preferred and common shareholders at the discretion of the company’s board of directors.

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 United States.

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 power plants.

Dore 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 drill holes; more work is required before reserves can be classified as probable or proven.

Dry – A building where the miner changes into working clothes.

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 rocks.


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 that act as starters or cathodes.

EM survey – A geophysical survey method that measures the electromagnetic properties of rocks.

En echelon – Roughly parallel but staggered structures.

Environmental impact study – A written report, compiled prior to a production decision, which examines the effects proposed mining activities will have on the natural surroundings.

Epigenetic – Ore bodies 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 shares.

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 glacial boulder.

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 drilling.


Fabricated fuel – Fuel assemblies composed of an array of fuel rods loaded with pellets of enriched uranium dioxide.

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 that have moved the rock on one side with respect to the other.

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, and others sink.

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 or matte.

Fluxgate magnetometer – An instrument used in geophysics to measure total magnetic field.

Flysch – Sediments produced by the erosion of uprising and developing fold structures, which are subsequently deformed by later stages in the development of these same fold structures.

Fold – Any bending or wrinkling of rock strata.

Footwall – The rock on the underside of a vein or ore structure.

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 United States.

Forward contract – The sale or purchase of a commodity for delivery at a specified future date.

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 categories.

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 fractures.

Free milling – Ores of gold or silver from which the precious metals can be recovered by concentrating methods without resort to pressure leaching or other chemical treatment.


Gabbro – A dark, coarse-grained igneous rock.

Galena – Lead sulfide, the most common ore mineral of lead.

Gamma – A unit of measurement of magnetic intensity.

Gangue – The worthless minerals in an ore deposit.

Geiger counter – An instrument used to measure radioactivity (e.g., that which emanates from certain minerals) by means of a Geiger-Mueller tube.

Geochemistry – The study of the chemical properties of rocks.

Geology – The science concerned with the study of the rocks, which compose the Earth.

Geomorphic – Pertaining to the form of the Earth or of its surface features: e.g. a geomorphic province.

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.

Geoscientific – Pertaining to the earth sciences and sciences specific to mineral exploration such as geology, geochemistry, geophysics, hydrology, etc.

Geothermal – Pertains to the heat of the Earth’s interior.

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 – A precious yellow metallic element, highly malleable and ductile, and not subject to oxidation or corrosion. Symbol: Au; atomic weight: 196.967; atomic number: 79; specific gravity: 19.3 at 20°C.

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 sulfides.

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 down faulted 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.

Greenfield Project – In many disciplines a greenfield is a project that lacks any constraints imposed by prior work. The analogy is to that of construction on greenfield land where there is no need to work within the constrains of existing buildings or infrastructure. In mining, land that has yet to be fully explored.

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 qualification.

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 made.

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 calcium sulfate.

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.

Hanging wall – The rock on the upper side of a vein or ore deposit.

Head grade – The average grade of ore fed into a mill.

Heap leaching – A process whereby valuable metals (usually gold and silver) are leached from a heap, or pad, of crushed ore by leaching solutions percolating down through the heap and are collected from a sloping, impermeable liner below the pad.

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 change.

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.

Highly enriched uranium (HEU) – Any form of uranium with a U-235 concentration of 20% or higher.

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 orebody.

Horst – An upfaulted block of rock.

Host rock – The rock surrounding an ore deposit.

Hydraulic filling – A variation of cut and fill stoping which involves returning carefully sized mill tailings in a slurry to the stopes underground, where the slurry is hosed into place as stope fill under the pressure developed by the head. Water quickly drains from the tailings fill, which becomes compact enough to support the weight of men and equipment as they continue to stope overhead. Hydraulic filling is a convenient way of combining the solutions to the stope fill and mill tailings disposal problems.

Hydrometallurgy – The treatment of ore by wet processes (e.g., leaching) resulting in the solution of a metal and its subsequent recovery.

Hydrothermal – Relating to hot fluids circulating in the Earth’s crust.


Igneous rocks – Rocks formed by the solidification of molten material from far below the Earth’s surface.

Ilmenite – An ore mineral of titanium, being an iron-titanium oxide.

Indicated Mineral Resource – An Indicated Mineral Resource is that part of a Mineral Resource for which quantity, grade or quality, densities, shape and physical characteristics, can be estimated with a level of confidence sufficient to allow the appropriate application of technical and economic parameters, to support mine planning and evaluation of the economic viability of the deposit. The estimate is based on detailed and reliable exploration and testing information gathered through appropriate techniques from locations such as outcrops, trenches, pits, workings and drill holes that are spaced closely enough for geological and grade continuity to be reasonably assumed.

Induced polarization – see IP

Industrial minerals – Non-metallic, non-fuel minerals used in the chemical and manufacturing industries. Examples are asbestos, gypsum, salt, graphite, mica, gravel, building stone and talc.

Inferred Mineral Resource – An Inferred Mineral Resource is that part of a Mineral Resource for which quantity and grade or quality can be estimated on the basis of geological evidence and limited sampling and reasonably assumed, but not verified, geological and grade continuity. The estimate is based on limited information and sampling gathered through appropriate techniques from locations such as outcrops, trenches, pits, workings and drill holes.

Initial public offering – The first sale of shares to the public, usually by subscription from a group of investment dealers.

In Situ Leaching 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% quartz.

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.

Intrusive Breccia – A rock in which angular fragments are surrounded by a mass of fine-grained minerals.

Ion exchange – An exchange of ions in a crystal with ions in a solution. Used as a method for recovering valuable metals, such as uranium, from solution.

IP – Induced polarization. A method of ground geophysical surveying employing an electrical current to determine indications of mineralization.


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 found in tropical countries out of which the silica has been leached. May form ore bodies 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 volcanoes.

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 originally.

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 meters or more apart.

Lignite – A soft, low-rank, brownish-black coal.

Lithology – (a) The description of rocks, esp. sedimentary clastics are esp. in hand specimen and in outcrop, on the basis of such characteristics as color, structures, mineralogic composition, and grain size. As originally used, “Lithology” was essentially synonymous with petrography as currently defined. (b) The physical character of a rock. —Adj: lithologic. Cf: petrology.

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 margin.

Long-term contract – One or more deliveries to occur after a year following contract execution.

Long-term price – The price for product sold or purchased under contract for multiple deliveries beginning after one year.

Long ton – 2,240 lbs. avoirdupois (compared to a short ton, which is 2,000 lb).


Mafic – Igneous rocks composed mostly of dark, iron- and magnesium-rich minerals.

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 magma.

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 practiced 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 broker as security for the loan holds the stock.

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”.

Material Event – News or details that may reasonably be expected to affect a company’s stock price and thus decisions that investors make about buying or selling the company’s stock. Material events must be made public and  fall under the jurisdiction of the USA Securities Exchange Commission.

Matte – A product of a smelter, containing metal and some sulfur, which must be refined further to obtain pure metal.

Measured Mineral Resource – A Measured Mineral Resource is that part of a Mineral Resource for which quantity, grade or quality, densities, shape, and physical characteristics are so well established that they can be estimated with confidence sufficient to allow the appropriate application of technical and economic parameters, to support production planning and evaluation of the economic viability of the deposit. The estimate is based on detailed and reliable exploration, sampling and testing information gathered through appropriate techniques from locations such as outcrops, trenches, pits, workings and drill holes that are spaced closely enough to confirm both geological and grade continuity.

Metadata – Data that describes other data. “Meta” is a prefix that in most information technology usages means an underlying definition or description.

Metallurgical coal – Coal used to make steel.

Metallurgy – The study of extracting metals from their ores.

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 – 1) A plant in which ore is treated and metals are recovered or prepared for smelting. 2) A revolving drum used for the grinding of ores in preparation for treatment.

Milling of uranium – The processing of uranium from ore mined by conventional methods, such as underground or open pit, to separate the uranium from the undesired material in the ore.

Milling ore – Ore that contains sufficient valuable mineral to be treated by milling process.

Millivolts – A measure of the voltage of an electric current, specifically, one-thousandth of a volt.

Mineable 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 form.

Mineral Exploration – ® Wikipedia Mineral Exploration Article

Mineral Reserve – A Mineral Reserve is the economically mineable part of a Measured or Indicated Mineral Resource demonstrated by at least a Preliminary Feasibility Study. This Study must include adequate information on mining, processing, metallurgical, economic and other relevant factors that demonstrate, at the time of reporting, that economic extraction can be justified. A Mineral Reserve includes diluting materials and allowances for losses that may occur when the material is mined.

Mineral Resource – A Mineral Resource is a concentration or occurrence of natural, solid, inorganic or fossilized organic material in or on the Earth’s crust in such form and quantity and of such a grade or quality that it has reasonable prospects for economic extraction. The location, quantity, grade, geological characteristics and continuity of a Mineral Resource are known, estimated or interpreted from specific geological evidence and knowledge.

Molybdenum – A gray, metallic element that resembles chromium and tungsten in many properties, is used esp. in strengthening and hardening steel, and is a trace element in plant and animal metabolism. Molybdenum’s low toxicity has also turned it into an important component of catalysts and lubricants, many of which are used by the oil industry.

Muck – 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 pile.


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 uranium.

Native metal – A metal occurring in nature in pure form, uncombined with other elements.

Natural source audio-range magneto-telluric – see NSAMT

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 liabilities.

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.

Norite – A coarse-grained igneous rock that is host to copper/nickel deposits in the Sudbury area of Ontario.

NSAMT – Natural source AMT. A type of AMT survey which uses naturally occurring EM waves generated by thunderstorms going on constantly around the world. see also CSAMT

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.

Nugget – A small mass of precious metal, found free in nature.


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.

Open stoping – A mining method wherein stopes are left largely open during mining. Small ore bodies are often mined completely out, leaving no pillar of ore in place to support the walls of the stope. In some kinds of rock, it is possible to mine out huge stopes which stand open for years. When some of the ore body is left in place as random pillars to support walls, the material is low-grade wherever possible because it may never be removed from the mine. Sometimes, after open stoping a mine, the pillars are “robbed” just before abandoning that portion of the mine, when the collapse of the stope walls is of no concern to the operation.

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 lower level.

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 mineral to be extracted profitably.

Organic maturation – The process of turning peat into coal.

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, i.e. that is not covered by soil or water,

Overturned – Where the oldest sedimentary rock beds are lying on top of a younger bed.

Oxidation – A chemical reaction caused by exposure to oxygen that results in a change in the chemical composition of a mineral.


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 project.

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; it 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 sulfide, the most common nickel ore.

Peridotite – An intrusive igneous rock consisting mainly of olivine.

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 operations.

Petrology – A general term for the study by all available methods of the natural history of rocks including ore deposits and mineral deposits.

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 purposes.

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 luster and is highly radioactive.

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 groundmass.

Porphyry copper – A deposit of disseminated copper (frequently with gold, molybdenum, silver, and zinc) 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.

Preliminary Feasibility Study – A comprehensive study of the viability of a mineral project that has advanced to a stage where the mining method, in the case of underground mining, or the pit configuration, in the case of an open pit, has been established, where an effective method of mineral processing has been determined, and includes a financial analysis based on reasonable assumptions of technical, engineering, legal, operating, and economic factors and evaluation of other relevant factors which are sufficient for a Qualified Person, acting reasonably, to determine if all or part of the Mineral Resource may be classified as a Mineral Reserve.

Price-to-earnings ratio – The current market price of a stock divided by the company’s net earnings per share for the year.

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 (to ownership, income or contribution).

Probable reserves – Valuable mineralization not sampled enough to accurately estimate the terms of tonnage and grade. Also called “indicated reserves.”

Processing of uranium – Uranium-recovery operations at a mill, in-situ leach plant, byproduct plant, or other type of recovery operation.

Profit and loss statement – The income statement of a company detailing revenues minus total costs to give total profit.

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 by issuing shares in the company.

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 “measured reserves.”

Proxy – A power of attorney given by the shareholder so that his stock may be voted by his nominee(s) at shareholders’ meetings.

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 sulfide mineral, normally of little value. It is sometimes referred to as “fool’s gold”.

Pyrrhotite – A bronze-colored, magnetic iron sulfide mineral.

Pyroclastic – Pertaining to clastic rock material formed by volcanic explosion or aerial expulsion from a volcanic vent; also, pertaining to rock texture of explosive origin. It is not synonymous with the adjective “volcanic”.


Quartz – Common rock-forming mineral consisting of silicon and oxygen.

Quartzite – A metamorphic rock formed by the transformation of 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 strike.

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 the hole.

Reclamation – The restoration of a site after mining or exploration activity is completed.

Reconnaissance – A preliminary survey of ground.

Reconnaissance induced polarization – see RIP

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 affect the full recovery of the valuable minerals.

Regional metamorphism – Metamorphism caused by both the heat of igneous processes and tectonic pressure.

Regolith – A general term for the entire layer of mantle of fragmental and loose, incoherent, or unconsolidated rock material, of whatever origin (residual or transported and of very varied character, that nearly everywhere forms the surface of the land and overlies or covers the more coherent bedrock.

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.

Resistivity survey – A geophysical technique used to measure the resistance of a rock formation to an electric current.

Resource – The calculated amount of material in a mineral deposit, based on limited drill information.

Resuing – A method of stoping in narrow-vein deposits whereby the wall rock on one side of the vein is blasted first and then the ore.

Resurgent cauldron – A cauldron (caldera) in which the cauldron block, following subsidence, has been uplifted, usually in the form of a structural dome (Smith & Bailey, 1968, p. 613).

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.

Rill stoping – A variation of cut and fill stoping wherein the slices are inclined to the horizontal, so that ore moves down out of the stope, and waste slides down into the stope from above, with the need for hand shoveling or mechanical scraping.

Rock – Any natural combination of minerals; part of the Earth’s crust.

RIP – Reconnaissance induced polarization. A subset of the IP methodology developed by Zonge Engineering and Research Organization Inc. of Tucson Arizona, whereby electrodes are laid out in a manner that IP response is measured over a large square or ovoid shape rather than along a line. The information gives indications or pinpoints mineralization within or over a broad area. It is generally followed up by dipole-dipole IP surveys along appropriate lines. The purpose as indicated by the name is to reconnoiter large areas at low cost.

Rockbolting – The act of supporting openings in rock with steel bolts anchored in holes drilled especially for this purpose.

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 meters 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 meters, while a tonne of dense sulfide ore may occupy only 0.25 cubic meters.

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 these stresses.

Rod mill – A rotating steel cylinder that uses steel rods as a means of grinding ore.

Room-and-pillar mining – A type of open stoping wherein pillars are left in place in a regular pattern while the rooms are mined out. In many room and pillar mines, the pillars are taken out, starting at the farthest point from the mine haulage exit, retreating, and letting the roof come down upon the floor. Room and pillar mining is well adapted to mechanization, and is commonly used in flat or gently dipping bedded deposits such as coal, potash, phosphate, salt, oil, shale, and bedded uranium ores.

Rotary drill – A machine that drills holes by rotating a rigid, tubular string of drill rods to which is attached a bit. Cuttings are flushed out of the bit, while cooling the bit, and brought to the surface by air or water-mud circulation. Commonly used for drilling large-diameter blast holes in open pit mines, as well oil well and water well drilling. For sampling mineral deposits, air circulation is preferably used above the water table. In rotary drilling, samples are chips and pulverized rock produced by the abrasive and chipping action of the drill bit.

Rotary reverse circulation (RC) drilling – RC drilling is similar to air drilling, in that the drill cuttings are returned to surface inside the rods. The drilling mechanism can be a tricone bit but now more commonly is a pneumatic reciprocating piston known as a “hammer” driving a tungsten-steel drill bit. RC drilling utilizes much larger rigs and machinery and depths of up to 500 meters are routinely achieved. Ideally, produces dry-rock chips above the water table.  Penetration below the water table is difficult because the heavy water is difficult for the air stream to lift and the hole generally “waters out” quickly.  Then the drilling would have to proceed with a water-mud circulation which generally results in an inferior mineral sample.See Intro to RC drilling [Atlas Copco PDF]

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 ton 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 loose term used to describe ore of average grade.


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 the public.

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.

Sand fill mining – see Hydraulic filling

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 shearing.

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 sulfide 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 large scale.

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 lb avoirdupois.

Shrinkage stoping – A mining method wherein the ore deposit is stoped from beneath, allowing broken ore to support the stope walls, but leaving a space above the broken ore just sufficient for the miners to stand on and drill overhead. Broken ore is drawn as necessary to maintain this headroom, and becasue the volume of rock expands upon breaking, about a third of the broken ore is drawn from beneath as stoping progresses from the bottom of the ore block to the top. After the stope is completed, all broken ore is removed and the walls are allowed to cave in. The wall rock must be strong enough to support itself during shrinkage stoping, without breaking away and becoming mixed with the broken ore. Steeply dipping veins with well-defined, hard walls are most suitable for shrinkage stoping.

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 sinter.)

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 dolostone formation.

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 shale.

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 – see SX-EW

Spelter – The zinc of commerce, more or less impure, cast from molten metal into slabs or ingots.

Sphalerite – A zinc sulfide 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 shares.

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 contract execution.

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.

Spot price – Current delivery price of a commodity traded in the spot market.

Spot market – The buying and selling of uranium products for delivery within one year.

Square set – A cubic frame of timber used to support the walls and roof of a stope.

Square-set stoping – A mining method wherein small blocks of ore are removed and replaced by a square set which is immediately set into place. The timber sets interlock and are filled with broken waste rock or sand fill, for they are not strong enough to support the stope walls. The waste rock or sand is usually added after one tier of sets, or stope cut, is made. Square-set stoping is used where the ore is weak, and the walls are not strong enough to support themselves. The value of the ore must be relatively high, for square-setting is slow, expensive, and requires highly skilled miners and supervisors.

Station – An enlargement of a shaft made for the storage and handling of equipment and for driving drifts at that elevation.

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 stock brokers who own seats on the exchange and meet membership requirements.

Stockpile – Broken ore heaped on surface, pending treatment or shipment.

Stope – An excavation in a mine from which ore is, or has been, extracted.

Stoping – American mining term for Underground methods of mining.

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 particular area.

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 transfer agent.

Striations – Prominent parallel scratches left on bedrock by advancing glaciers.

Strike – The direction, or bearing from true north, of a vein or rock formation measured 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 mine.

Strip mine – An open pit mine, usually a coal mine, mined by removing overburden, excavating the coal seam, then returning the overburden.

Stull – A beam.

Stull Stoping – A type of open stoping used for narrow veins, wherein an occasional wood stull is placed from one wall of the stop to the other. The stulls serve to support the vein walls, and as places to anchor wood platforms upon which the miners and equipment stand while drilling ore overhead.

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 the shares (a controlling position) is held by another company.

Sulfide – A compound of sulfur and some other element.

Sulfide dust explosions – An underground mining hazard involving the spontaneous combustion of airborne dust containing sulfide minerals.

Sulfur dioxide – A gas liberated during the smelting of most sulfide ores; either converted into sulfuric 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.

SX-EW – Solvent extraction-Electrowinning. 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.

Syenite – An intrusive igneous rock composed chiefly of orthoclase.

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 ore.

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.

Till – Nonsorted, nonstratified sediment carried or deposited by a glacier.

Tonnes-per-vertical-meter – 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 meter 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 treasury.

Trench – A long, narrow excavation dug through overburden, or blasted out of rock, to expose a vein or ore structure.

Trend – The direction, in the horizontal plane, of a linear geological feature (for example, an ore zone), measured from true north.

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.

Tundra – One of the level or undulating treeless plains characteristic of arctic regions, having a black muck soil and permanently frozen subsoil.

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.


U-235 – The only naturally occurring isotope of uranium which is capable of fission and is present in approximately 0.71% by weight in natural uranium.

U3O8 – Triuranium octoxide. It is in the form of concentrate, often called yellowcake. 1 lb. U in U308 = 1.17924 lbs. U308.

UF6 – Uranium hexafloride, a compound of uranium produced during the conversion process, which is a gas above 56 degrees Celsius and thus suitable for use in the enrichment process of U3O8 into fuel for nuclear reactors.

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 formula.

Underwrite – A firm commitment made by a broker or other financial institution to purchase a block of shares at a specified price.

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.

Uranium – 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 nuclear industry 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 production.

Uranium deposit – A discrete concentration of uranium mineralization that is of possible economic interest.

Uranium Deposit Types – See below

Unconformity-Related Uranium Deposits – Unconformity related deposits are related to breaks in the stratigraphic record, or “unconformities”. These breaks generally occur around the contact between >500 million year old permeable sedimentary basins which sit above a uranium-enriched, carbon-rich hard rock basement that has been weathered and usually structurally deformed. The deposits can be in the basin, at the contact between basin and basement, or in the upper part of the basement rocks themselves. Major fault systems and hydrothermal fluids provide the other key ingredients to create deposits. Unconformity deposits can have very high grades of uranium (20% and beyond), and in 2004 deposits of this type produced over 40% the worlds uranium.

Sandstone Uranium Deposits – Sandstone uranium deposits are typically formed in continental clastic basins with complex, deformed stratigraphy and structure. They are a result of the chemical transport of uranium but the source and time of emplacement is typically not known. They can form as tabular or lens-shaped bodies, roll-fronts, or channels within the host rock. Permeability of the sandstone, and efficient dissolution and deposition mechanisms all influence the formation of deposits. Grades for this deposit type are typically 0.15 — 0.4% U308 and deposits are usually small to medium sized but numerous within an area. Sandstone uranium deposits are widely distributed around the world and produced more than 11 % of global production in 2004. Niger, Kazakhstan, USA, and Australia were some of the leading producers of uranium from sandstone deposits.

Iron Oxide Copper-Gold (IOCG) Uranium Deposits – The IOCG deposit is a complex type of system that is often mined for copper and gold but can also contain a significant amount of uranium. This type of deposit is typified by its main example, the world’s largest uranium deposit, Olympic Dam. Olympic Dam contains approximately 1 billion pounds of U308 in reserve and produced more than 9% of the world’s uranium in 2004. The Olympic Dam deposit formed when hot mineral- rich fluids from a deep source penetrated a higher granite host rock to cause brecciation and mineral deposition. Olympic Dam is localized at the intersection of major structures and has an associated magnetic and gravity anomaly. Mineralization includes copper, uranium, gold, silver, light rare earth elements and iron oxides. The age of the Olympic Dam host rocks and deposit are the same and are comparable to the ages of the Central Mineral Belt uranium district.

Pegmatite-Intrusive (Rossing-style) Uranium Deposits – Rio Tinto’s Rossing pegmatite-intrusive deposit in Namibia produces nearly 8% of the world’s uranium annually. Rossing is a world class deposit and an important model for uranium exploration globally, including Labrador’s Central Mineral Belt (CMB). The Rossing deposit is characterized by disseminated uranium mineralization (dominantly uraninite) in a granite-like rock body in areas that have been subjected to intense metamorphism. Copper sulphides, molybdenite, arsenopyrite, iron oxides and fluorite are often associated with the ore. The deposit and others in its class are considered to possibly represent the deeper geologic equivalents of the higher level Olympic Dam-IOCG model. Therefore, the two models can both be applied in certain uranium districts, such as the CMB.

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 practices.

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 category.

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 traveled upwards from some deep source.

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 that 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 volcano.

Volcaniclastic – Pertaining to a clastic rock containing volcanic material in whatever proportion, and without regard to its origin or environment.

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 hanging wall and footwall rocks of an orebody.

Warrant – see Rights

Waste – Unmineralized, or sometimes-mineralized rock that is not mineable 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 difficult terrain.

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 profit.


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.(See uranium oxide).

Yield – The current annual dividend rate expressed as a percentage of the current market price of the stock.


Zone – An area of distinct mineralization.

Zone of oxidation – The upper portion of an orebody that has been oxidized.