Snow and rain that have a low pH, caused by sulphur dioxide and nitric oxide gases from industrial activity released into the atmosphere.

Igneous rock carrying a high (greater than 65%) proportion of silica.

An opening driven horizontally into the side of a mountain or hill for providing access to a mineral deposit.

Mining in the same direction, or order of sequence; first mining as distinguished from retreat.

An instrument used to measure magnetic field strength from an airplane.

A geophysical survey using a magnetometer aboard, or towed behind, an aircraft.

A breccia composed largely or entirely of fragments of volcanic rocks.

A method of concentrating valuable minerals based on their adhesion properties.

In metallurgy, the act or state of being stirred or shaken mechanically, sometimes accomplished by the introduction of compressed air.

Usually an abandoned shaft which has been intersected during the normal course of following the common denominator (e.g., a quartz vein) or driven a small distance to or along a vein to a known abandoned or disused shaft. An intersection provides ventilation. Two entrances to the surface provide a natural airflow, hence the term airshaft.

The division of a current of air into two or more parts.

A survey made from an air craft to obtain photographs, or measure magnetic properties, radioactivity, etc.

Any passage through which air is carried. Also known as an air course.

A compound of two or more metals.

Relatively recent deposits of sedimentary material laid down in river beds, flood plains, lakes, or at the base of mountain slopes. (adj. alluvial)

Any physical or chemical change in a rock or mineral subsequent to its formation. Milder and more localized than metamorphism.

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

The gradual and systematic writing off of a balance in an account over an appropriate period.

Acronym for ammonium nitrate and fuel oil, a mixture used as a blasting agent in many mines.

A rectangular plate of metal cast in a shape suitable for refining by the electrolytic process.

Any departure from the norm which may indicate the presence of mineralization in the underlying bedrock.

An arch or fold in layers of rock shaped like the crest of a wave.

The top or terminal edge of a vein on surface or its nearest point to the surface.

An underground geological zone which is able to store or conduct water in reasonably large quantities.

The testing of a sample of ore to determine the content of valuable minerals.

The assay value multiplied by the number of feet, metres, inches, centimetres across which the sample is taken.

Plan view of an area indicating assay values and locations of all samples taken on the property.

The amount of work, specified by mining law, that must be performed each year in order to retain legal control of mining claims.

The process of grinding ore in a rotating cylinder using large pieces of the ore instead of conventional steel balls or rods.

The ceiling or roof of an underground opening.

Rock chips collected from the roof or back of an underground opening for the purpose of determining grade.

Waste material used to fill the void created by mining an orebody.

Minor amounts of radioactivity due not to abnormal amounts of radioactive minerals nearby, but to cosmic rays and minor residual radioactivity in the vicinity.

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.

The use of bacteria to oxidise sulphide minerals.

A partition or grating in a furnace, container or channel.

Device for removing sludge and water from a drill hole or mine.

A formal statement of the financial position of a company on a particular day, normally presented to shareholders once a year.

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.

A bedded deposit of iron minerals.

Centre of operations from which exploration activity is conducted.

Any non-precious metal (eg. copper, lead, zinc, nickel, etc.).

The underlying or older rock mass. Often refers to rocks of Precambrian age which may be covered by younger rocks.

Igneous rocks that are relatively low in silica and composed mostly of dark-colored minerals.

A rock made up of hydrous aluminum oxides; the most common aluminum ore.

Term used to describe market conditions when share prices are declining.

The arrangement of sedimentary rocks in layers.

To concentrate or enrich; often applied to the preparation of iron ore for smelting.

A clay with great ability to absorb water and which swells accordingly.

A process for recovering metals from low-grade ores by dissolving them in solution, the dissolution being aided by bacterial action.

A platy magnesium-iron mica, common in igneous rocks.

The cutting end of a drill frequently made of an extremely hard material such as industrial diamonds or tungsten carbide.

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.

A mine employee responsible for loading, priming and detonating blastholes.

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

An inexpensive method of mining in which large blocks of ore are undercut, causing the ore to break or cave under its own weight.

One hundred shares.

An agreement to pay a certain amount of interest over a given period of time.

A telescoping, hydraulically powered steel arm on which drifters, manbaskets and hydraulic hammers are mounted.

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

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

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

The ore in a mine which has been broken by blasting but which has not yet been transported to surface.

Any large-scale, mechanized method of mining involving many thousands of tonnes of ore being brought to surface per day.

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.

Term used to describe financial market conditions when share prices are going up.

A prospector’s term for white, coarse-grained, barren quartz.

Metal formed into bars or ingots.

A secondary metal or mineral product recovered in the milling process.

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

Name given to concentrate that is ready for smelting (i.e. the sulphur has been driven off by oxidation).

An option to buy shares at a specified price. The opposite of a put.

The total ownership of a limited liability company divided among a specified number of shares.

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.

A stope that is accessible only through a manway.

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.

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.

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

A sulphide mineral of copper common in the zone of secondary enrichment.

The mine building where workers change into work clothes; also known as the dry.

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.

A document issued by a governing authority creating a company or other corporation.

A financial institution that accepts deposits and provides loans.

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.

An opening, usually constructed of timber and equipped with a gate, through which ore is drawn from a stope into mine cars.

A vermilion-colored ore mineral of mercury.

Over-sized chunks of ore returned to the head of a closed grinding circuit before going on to the next stage of treatment.

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).

Process of clearing dirty water by removing suspended material.

A mineral-processing machine which separates minerals according to size and density.

A fine-grained material composed of hydrous aluminum silicates.

The tendency of a mineral to split along crystallographic planes.

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.

A carbonaceous rock mined for use as a fuel.

The metamorphic processes of forming coal.

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

A milling process, carried out in a tall cylindrical column, whereby valuable minerals are separated from gangue minerals based on their wetability properties.

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.

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.

A fine, powdery product of the milling process containing a high percentage of valuable metal.

A milling plant that produces a concentrate of the valuable minerals or metals. Further treatment is required to recover the pure metal.

A machine which crushes ore between a gyrating cone or crushing head and an inverted, truncated cone known as a bowl.

A form delivered by a broker to the client, setting forth the details of stock sales or purchases for the client.

A sedimentary rock consisting of rounded, water-worn pebbles or boulders cemented into a solid mass.

A geological term used to describe the line or plane along which two different rock formations meet.

Metamorphism of country rocks adjacent to an intrusion, caused by heat from the intrusion.

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.

The long cylindrical piece of rock, about an inch in diameter, brought to surface by diamond drilling.

That part of a string of tools in a diamond drill hole in which the core specimen is collected.

Loosely used to describe the general mass of rock adjacent to an orebody. Also known as the host rock.

A horizontal opening driven from a shaft and (or near) right angles to the strike of a vein or other orebody.

The outermost layer of the Earth; includes both continental and oceanic crust.

A chemical species containing carbon and nitrogen used to dissolve gold and silver from ore.

A method of stoping in which ore is removed in slices, or lifts, and then the excavation is filled with rock or other waste material (backfill), before the subsequent slice is extracted.

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.

Drilling to establish accurate estimates of mineral reserves.

A common basic igneous rock usually occurring in dykes or sills.

The hardest known mineral, composed of pure carbon; low-quality diamonds are used to make bits for diamond drilling in rock.

A rotary type of rock drill that cuts a core of rock that is recovered in long cylindrical sections, two cm or more in diameter.

Rock that is removed along with the ore in the mining process, subsequently lowering the grade of the ore.

A decrease in the value of a company’s shares caused by the issue of treasury shares.

The angle at which a vein, structure or rock bed is inclined from the horizontal as measured at right angles to the strike.

A compass with the needle mounted so as to swing in a vertical plane, used for prospecting to determine the magnetic attraction of rocks.

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

Ore carrying small particles of valuable minerals spread more or less uniformly through the host rock.

An underground opening at the bottom of a stope through which broken ore from the stope is extracted.

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.

A long and relatively thin body of igneous rock that, while in the molten state, intruded a fissure in older rocks.

An electric current is passed through a solution containing dissolved metals, causing the metals to be deposited onto a cathode.

The process of purifying metal ingots that are suspended as anodes in an electrolytic bath, alternated with refined sheets of the same metal which act as starters or cathodes.

A geophysical survey method which measures the electromagnetic properties of rocks.

A written report, compiled prior to a production decision, that examines the effects proposed mining activities will have on the natural surroundings.

Orebodies formed by hydrothermal fluids and gases that were introduced into the host rocks from elsewhere, filling cavities in the host rock.

A mineral deposit consisting of veins and replacement bodies, usually in volcanic or sedimentary rocks, containing precious metals or, more rarely, base metals.

End of a drift, crosscut or stope in which work is taking place.

A break in the Earth’s crust caused by tectonic forces which have moved the rock on one side with respect to the other.

Containing iron.

An extensive crack, break or fracture in rocks.

Pieces of rock broken off and relocated by natural forces such as frost or glacial action.

Milling process in which valuable mineral particles are induced to become attached to bubbles and float as others sink.

Instrument used in geophysics to measure total magnetic field.

Bending or wrinkling of rock strata.

Rock on the underside of a vein or ore structure.

Break in the rock, the opening of which allows mineral-bearing solutions to enter.

A dark, coarse-grained igneous rock.

Lead sulphide, the most common ore mineral of lead.

A unit of measurement of magnetic intensity.

The worthless minerals in an ore deposit.

Instrument used to measure the radioactivity emanating from certain minerals by means of a Geiger-Mueller tube.

Pertains to the heat of the Earth’s interior.

Sedimentary material that has been transported by glaciers.

Lines or scratches on a smooth rock surface caused by glacial abrasion.

Fine, putty-like material composed of ground-up rock found along a fault.

A coarse-grained intrusive igneous rock consisting of quartz, feldspar and mica.

Sealing off water flow in rocks by forcing a thin slurry of cement or other chemicals into the crevices; usually done through a diamond drill hole.

A sedimentary rock consisting of hydrated calcium sulphate.

Rock salt.

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

Average grade of ore fed into a mill.

Taking a buy or sell position in a futures market opposite to a position held in the cash market, to minimize risk of financial loss from an adverse price change.

Fine-grained contact metamorphic rock.

An upfaulted block of rock.

Rock surrounding an ore deposit.

Treatment of ore by wet processes, e.g., leaching, resulting in the solution of a metal and its subsequent recovery.

Relating to hot fluids circulating in the earth’s crust.

Rocks formed by the solidification of molten material from far below the earth’s surface.

Ore mineral of titanium, being an iron-titanium oxide.

Method of ground geophysical surveying employing an electrical current to determine indications of mineralization.

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

Igneous rock containing 52% to 66% quartz.

Body of igneous rock formed by the consolidation of magma intruded into other rocks, in contrast to lavas, which are extruded upon the surface.

A machine in which rock is broken by the action of steel plates.

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.

Type of peridotite; the most common host rock of diamonds.

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.

Igneous rock, composed of dark minerals, that occurs in dykes; sometimes contains diamonds.

A residual soil, ususally found in tropical countries, out of which the silica has been leached. May form orebodies of iron, nickel, bauxite and manganese.

A chute or trough for conveying pulp, water or powdered ore in a mill.

General name for the molten rock ejected by volcanoes.

Extractable by chemical solvents.

Chemical process for the extraction of valuable minerals from ore; also, a natural process by which ground waters dissolve minerals.

Generally used to describe a body of ore that is thick in the middle and tapers towards the ends.

A deposit having roughly the form of a double convex lens.

Horizontal openings on a working horizon in a mine.

A mineral deposit in solid rock.

A major bidding market for base metals, which operates daily in London.

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

Molten material deep in the Earth from which rocks are formed.

An ore-forming process whereby valuable minerals are concentrated by settling out of a cooling magma.

Geophysical survey that measures the intensity of the Earth’s magnetic field.

Instrument used to measure the magnetic attraction of underlying rocks.

A metamorphic rock derived from the recrystallization of limestone under intense heat and pressure.

The study of extracting metals from their ores.

Rocks which have undergone a change in texture or composition as the result of heat and/or pressure.

The process by which the form or structure of rocks is changed by heat and pressure.

A plant in which ore is treated and metals are recovered or prepared for smelting; also a revolving drum used for the grinding of ores in preparation for treatment.

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

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

Ore reserves that are known to be extractable using a given mining plan.

Ore or rock that has been broken by blasting.

A representative piece of ore that is taken from a muck pile and then assayed to determine the grade of the pile.

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

A mine that is entirely on surface. Also referred to as open-cut or open-cast mine.

An agreement to purchase a property reached between the property vendor and some other party who wishes to explore the property further.

The right to buy or sell a share at a set price, regardless of market value.

A mixture of ore minerals and gangue from which at least one of the metals can be extracted at a profit.

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.

A natural concentration of valuable material that can be extracted and sold at a profit.

An exposure of rock or mineral deposit that can be seen on surface, not covered by soil or water.

There the oldest sedimentary rock beds are lying on top of a younger beds.

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

A coarse-grained, igneous rock, generally coarse, but irregular in texture, and similar to a granite in composition; usually occurs in dykes or veins and sometimes contains valuable minerals.

A term used to describe the coarse-grained texture of some igneous rocks.

A deposit of sand and gravel containing valuable metals such as gold, tin or diamonds.

Refers to rocks of igneous origin that have come from great depth.

The last in a series of settling ponds through which mill effluent flows before being discharged into the natural environment.

Estimate its tonnage and grade, or verify its existence. Also called inferred reserves.

The oldest, most stable regions of the earth’s crust, the largest of which is the Canadian Shield.

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

Valuable minerals deposited during the original period/s of mineralization, as opposed to those deposited as a result of alteration or weathering.

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

A document filed with the appropriate securities commission detailing the activities and financial condition of a company seeking funds from the public through the issuance of shares.

Reserves 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.

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

Common rock-forming mineral consisting of silicon and oxygen.

Metamorphic rock formed by the transformation of sandstone by heat and pressure.

The property of spontaneously emitting alpha, beta or gamma rays by the decay of the nuclei of atoms.

A geochemical survey technique which detects traces of radon gas, a product of radioactivity.

A vertical or inclined underground working that has been excavated from the bottom upward.

The trend of an orebody along the direction of its strike.

Relatively scarce minerals such as niobium and yttrium.

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.

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

A preliminary survey of ground.

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.

The percentage of valuable metal in the ore that is recovered by metallurgical treatment.

Ore that resists the action of chemical reagents in the normal treatment processes and which may require pressure leaching or other means to effect the full recovery of the valuable minerals.

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

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.

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

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

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

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

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.

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

A machine that drills holes by rotating a rigid, tubular string of drill rods to which is attached a bit. Commonly used for drilling large-diameter blastholes in open-pit mines.

A term used loosely to describe ore of average grade.

Selecting a fractional but representative part of a mineral deposit for analysis.

A sedimentary rock consisting of grains of sand cemented together.

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.

An escarpment, cliff or steep slope along the margin of a plateau, mesa or terrace.

Secondary rocks formed from material derived from other rocks and laid down under water. Examples are limestone, shale and sandstone.

A geophysical method of prospecting, utilizing knowledge of the speed of reflected sound waves in rock.

A method of grinding rock into fine powder by means of larger chunks of rocks and steel balls.

Sedimentary rock formed by the consolidation of mud or silt.

A concentration of mineral values; that part of a vein or zone carrying values of ore grade.

2,000 lbs. avoirdupois.

Stoping method which uses part of the broken ore as a working platform and as support for the walls of the stope.

Rock containing an abundance of quartz.

An intrusive sheet of igneous rock of roughly uniform thickness that has been forced between the bedding planes of existing rock.

Muddy deposits of fine sediment usually found on the bottoms of lakes.

The vitreous mass separated from the fused metals in the smelting process.

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

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

Prominent parallel scratches left on bedrock by advancing glaciers.

The direction, or bearing from true north, of a vein or rock formation measure.

To remove the overburden or waste rock overlying an orebody in preparation for mining by open pit methods.

An open-pit mine, usually a coal mine, operated by removing overburden, excavating the coal seam, then returning the overburden.

The ratio of tonnes removed as waste relative to the number of tonnes of ore removed from an open-pit mine.

Industrial development that does not detract from the potential of the natural environment to provide benefits to future generations.

Material rejected from a mill after most of the recoverable valuable minerals have been extracted.

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.

Common unit used to describe the amount of ore in a deposit; ore length is multiplied by the width and divided by the appropriate rock factor to give the amount of ore for each vertical metre of depth.

The direction, in the horizontal plane, of a linear geological feature, such as an ore zone, measured from true north.

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.

An assay made by a third party to provide a basis for settling disputes between buyers and sellers of ore.

The actual assay value of a core sample as opposed to a cut value which has been reduced by some arbitrary formula.

Unmineralized, or sometimes mineralized, rock that is not minable at a profit.

A technique of directing a diamond drill hole in a desired direction away from its current orientation.

An internal shaft.

A fragment of country rock enclosed in an intrusive rock.

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

An area of distinct mineralization.

The upper portion of an orebody that has been oxidized.