Glosario Minero
Explora nuestro completo glosario de términos y definiciones utilizados en la industria minera
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Acid mine drainage
Acidic runoff or groundwater associated with mine workings, waste dumps or tailings facilities containing sulphides, generated by oxidation of those minerals.
Acidic rocks
Igneous rocks with a high proportion of silica, generally greater than 65%.
Adit
A horizontal opening driven into a hillside or mountain to provide access to a mineral deposit.
Aeromagnetic survey
A geophysical survey carried out with a magnetometer installed on or towed by an aircraft.
Agglomerate
A breccia composed mostly or entirely of rounded fragments of volcanic rocks.
Agglomeration
The process of binding or cementing crushed or ground rock particles into larger pieces, generally to improve handling; commonly used in heap leaching.
Agitation
In metallurgy, the mechanical stirring or mixing of a pulp or solution, sometimes by injecting compressed air.
Airborne magnetometer
An instrument used to measure magnetic field intensity from an aircraft.
Airborne reconnaissance
A survey carried out from an aircraft to obtain photographs or measure properties such as magnetism, radioactivity or other geophysical variables.
Alloy
A metallic material formed by combining two or more elements, at least one of which is a metal.
Alluvium
Relatively recent sedimentary material deposited in river channels, floodplains, lakes or at the foot of mountain slopes. Adjective: alluvial.
Alpha meter
An instrument used to measure alpha particles, positively charged particles emitted by radioactive materials.
Alpha rays
Positively charged particles emitted by certain radioactive materials.
Alteration
Chemical changes in minerals after the formation of a rock or deposit, typically caused by reactions between mineralizing fluids and host rocks, as well as by surface weathering. C...
American depositary receipts (ADR)
Negotiable certificates traded in United States markets that represent shares of a foreign company deposited with a U.S. bank or trust company.
Amorphous
A term applied to rocks or minerals with no crystalline structure or definite form, such as amorphous carbon and obsidian.
Amortization
An accounting charge that allocates capitalized costs over time, such as pre-production costs. It does not necessarily involve a cash outflow, but reduces taxable income.
Amphibolite
A metamorphic rock composed mainly of amphibole minerals and plagioclase.
ANFO (ammonium nitrate fuel oil)
Acronym for ammonium nitrate and fuel oil; a mixture used as a blasting agent in many mines.
Annual report
Formal financial statements and operating reports issued by a corporation to its shareholders at the end of its fiscal year.
Anode
A plate or piece of cast metal that acts as the positive electrode in an electrolytic refining process.
Anomaly
A deviation from a normal value or pattern that may indicate mineralization in the underlying bedrock.
Anthracite
A hard, black, lustrous coal with a high fixed-carbon content and low volatile-matter content.
Anticline
An upward-convex fold in rock layers, similar in form to an arch.
Antiform
A fold similar to an anticline, but in which the relative ages of the folded rocks are unknown.
Apex
The upper part or terminal end of a vein at the surface, or at the point nearest to the surface.
Aqua regia
A solution of three parts hydrochloric acid and one part nitric acid; one of the few solvents capable of dissolving gold. Its name, Latin for royal water, comes from medieval alche...
Ash
Inorganic residue remaining after coal is ignited.
Assay
A chemical test performed on an ore or mineral sample to determine the amount of valuable metals it contains.
Assay length product
The assay value multiplied by the sample length, expressed in feet, metres, inches or centimetres. It is used to calculate weighted average grades.
Assay map
A plan view of an area showing assay values and the locations of all samples taken on the property.
Assay ton
An assay charge of 29.166 grams. A sample of that weight produces a gold bead whose weight in milligrams is equivalent to the original grade in troy ounces per short ton.
Assessment work
The amount of work specified by mining law that must be performed each year to maintain legal control of mineral claims.
Atomic absorption spectrophotometry
An instrumental chemical analysis method that identifies metal atoms by the wavelengths of light they absorb. It remains one of the fastest and most precise analytical methods.
Authorized capital
See capital stock.
Autogenous grinding
Grinding in a rotating cylinder using large fragments of the ore itself as the grinding medium, instead of steel balls or rods.
Back
The roof or upper part of an underground excavation.
Back or floor sample
Rock fragments collected from the back or floor of an underground working to determine grade.
Backfill
Waste material used to fill the void created by mining a mineral deposit.
Background
Background radioactivity not associated with anomalous concentrations of nearby radioactive minerals, but with cosmic rays and natural residual radioactivity.
Backwardation (futures market)
A situation in which the spot price of a metal is higher than the price for future delivery.
Balance sheet
A financial statement showing a company's financial position at a specific date.
Ball mill
A steel cylinder charged with steel balls and crushed ore; as it rotates, the balls cascade and grind the ore.
Banded iron formation
A stratified iron-mineral deposit.
Bankable
Acceptable to lenders as a basis for project financing; used especially for definitive feasibility studies.
Basal till
Unsorted glacial debris deposited at the base of a glacier, in direct contact with bedrock.
Basalt
An extrusive volcanic rock composed mainly of plagioclase, pyroxene and some olivine.
Base camp
The operations center from which exploration activities are directed.
Base metal
Any non-precious metal, such as copper, lead, zinc or nickel.
Basement rocks
An underlying or older rock mass, often Precambrian, that may be covered by younger rocks.
Basic rocks
Igneous rocks with relatively low silica content, composed mostly of dark-colored minerals.
Batholith
A large mass of intrusive igneous rock extending to great depth, commonly with a domed upper surface. Smaller similar intrusive bodies are known by other names, such as stocks or p...
Bauxite
A rock composed of hydrated aluminum oxides; the principal ore of aluminum.
Bear market
Market conditions in which share prices are falling.
Bearing
The direction, in a horizontal plane, of a linear geological feature such as a mineralized zone, measured from true north.
Bench-scale testing
Preliminary metallurgical testing at laboratory scale to determine whether metal can be extracted from a mineralized sample.
Beneficiate
To concentrate or enrich a mineral; often applied to preparing iron ore before smelting.
Bentonite
A clay with high water-absorption capacity that swells or expands when hydrated.
Bioleaching
A process for recovering metals from low-grade minerals by dissolving them in solution, aided by microbial activity.
Biotite
An iron- and magnesium-rich mica, common in igneous and metamorphic rocks.
Bit
The cutting end of a drill bit, usually made from very hard materials such as industrial diamond or tungsten carbide.
Black smoker
A hydrothermal vent in active seafloor-spreading areas through which sulphide-rich fluids escape.
Blackjack (sphalerite)
A mining term for sphalerite, zinc sulphide.
Blast furnace
A vertical reaction furnace charged with ores, fluxes and fuels, and supplied with hot air to chemically reduce metal oxides to metal.
Blast hole
A drill hole loaded with explosives to fragment a specified amount of rock.
Blasted reserves
Ore in a mine that has been broken by blasting but has not yet been transported to surface or to the plant.
Blaster
A mine employee responsible for loading, priming and detonating blast holes.
Blasting agent
A relatively insensitive material that can react with other chemical compounds to form an explosive mixture. The most common blasting agent is ammonium nitrate.
Blister copper
An impure form of copper, about 99% pure, produced in smelting and requiring further refining before industrial use.
Block caving
A bulk mining method in which a large block of ore is undercut to induce fracturing and caving under gravity.
Block model
A model of a mineral deposit divided into small volumes for resource and reserve estimation and mine planning. It may be a physical model or a computer model.
Board lot
A standard lot of shares traded on an exchange; usually one hundred shares, although it may vary by market and share price.
Bond
A debt instrument under which the issuer pays interest over a specified period and repays principal at maturity; it may be backed by assets as security.
Bought deal
A firm commitment by a broker or other financial institution to purchase a block of shares at a specified price.
Boxhole
A short raise or opening above a drift used to draw ore from a stope or to provide access.
Break
A broad term used for a structural fault or large regional shear zone.
Breccia
A rock in which angular fragments are enclosed in a finer-grained matrix. Breccias may form by structural, intrusive or hydrothermal processes.
Brunton compass
A pocket compass equipped with sights and a mirror, used to take bearings, measure inclinations and carry out preliminary surveys.
Bulk leach extractable gold
A geochemical analytical technique using a large soil or rock sample, typically about 1 kg, from which gold is extracted by leaching with sodium cyanide or aqua regia. It gives a r...
Bulk mining
A large-scale mechanized method that can extract and move thousands of tonnes of ore per day.
Bulk sample
A large sample of mineralized rock, often hundreds of tonnes, selected to be representative of the potential deposit and used to determine metallurgical characteristics.
Bull market
Financial market conditions in which share prices are rising.
Bull quartz
A prospecting term for white, massive, coarse-grained quartz, generally without visible economic mineralization.
By-product
A secondary metal, mineral or other product recovered during the extraction, processing or refining of a primary mineral.
Cage
The conveyance used to transport workers and equipment between the surface and underground mine levels.
Calcine
Material produced by calcination, that is, by heating ore or concentrate to remove volatile compounds, oxidize sulphides or eliminate other impurities.
Call option
An option giving the right to buy shares at a specified price within a specified period.
Capital stock
The total share capital represented by the issued shares of a company.
Capitalization
The total market value assigned to a company, generally calculated by multiplying the number of outstanding shares by the current share price.
Captive stope
A stope accessible only by a ladder or other restricted access.
Carat
A purity unit equal to one part in 24, used to express the proportion of pure precious metal in an alloy.
Carbon-in-leach
A gold recovery method in which activated carbon particles circulate in the leach solution.
Carbon-in-pulp
A method for recovering gold and silver from cyanide solutions by adsorbing the precious metals onto activated carbon granules, commonly produced from coconut shells.
Carbonization
Metamorphic processes involved in the formation of coal.
Cash flow
Net inflow and outflow of money during an accounting period. It excludes depreciation and amortization charges that do not involve cash payments.
Cathode
A rectangular plate of metal produced by electrolytic refining and later melted into commercial forms such as wire bars or ingots.
Cesium magnetometer
A geophysical instrument that measures magnetic field intensity, either as vertical gradient or total field.
Chalcocite
A copper sulphide common in zones of secondary enrichment.
Chalcopyrite
A copper-iron sulphide and the most common ore mineral of copper.
Change house
A building where mine workers change into work clothes.
Channel sample
A composite sample of pieces cut from a vein or mineralized body along a regular channel, typically about 10 cm wide and 2 cm deep.
Chargeability
The effect measured in an induced-polarization survey, defined as the residual voltage after the current is cut off divided by the applied voltage.
Charter
A document issued by a government authority creating a company or corporation.
Chartered bank
A financial institution that accepts deposits and makes loans.
Chip sample
A rock sampling method in which a regular series of small chips is broken from exposed rock along a line on the surface.
Chromite
The principal ore of chromium.
Chute
An opening, usually timbered and fitted with a gate, through which ore is drawn from a stope or bench into mine cars or another haulage system.
Cinnabar
A vermilion-colored mercury mineral.
Circulating load
Oversize material returned to the head of a closed grinding circuit before passing to the next treatment stage.
Claim
An area of ground over which a prospector or mining company holds a mineral right or claim.
Clarification
The process of removing suspended material from turbid water to make it clear.
Classifier
Mineral-processing equipment that separates particles by size, density or other classification properties.
Clastic rock
A rock formed from fragments or clasts rather than intergrown crystals. In a volcanic sense, it includes pyroclastic rocks such as tuff, lapilli tuff, agglomerate or breccia.
Clay
Fine-grained material composed mainly of hydrated aluminum silicates.
Closed circuit
A grinding or classification circuit in which a selected fraction of the product is returned to the feed end to meet the required specification.
Coal
A carbonaceous rock mined for use as fuel.
Collar
A term applied to timber or concrete around the mouth of a shaft; also used to describe the top of a drill hole.
Column flotation
A milling process carried out in a tall cylindrical column in which valuable minerals are separated from gangue according to surface wettability properties.
Complex ore
Ore containing several minerals of economic value. The term often implies metallurgical difficulty in liberating and separating the valuable metals.
Concentrator
A plant or unit that produces a concentrate of valuable minerals or metals, which then requires additional treatment to recover the metal.
Cone crusher
A machine that crushes ore between a rotating cone or crushing head and a fixed truncated-cone surface.
Confirmation
A document sent by a broker to a client detailing a purchase or sale of shares.
Conglomerate
A sedimentary rock composed of water-rounded pebbles or rounded clasts cemented into a solid mass.
Contact
A geological term for the line or plane where two different rock formations meet.
Contact metamorphism
Metamorphism of host rocks adjacent to an intrusion, caused mainly by the heat of that intrusion.
Contango (futures market)
A situation in which the price of a metal for future delivery is quoted above the spot price.
Continuous miner
A piece of mining equipment that produces a continuous flow of ore from the working face.
Controlled blasting
Blast designs and sequences used to achieve a specific objective, such as directing muck displacement or detonating charges in stages.
Convertible security
A bond or debenture that can be converted into shares at the option of the holder or issuer, according to a predetermined formula and conditions.
Cordillera (mountain chain)
A continuous chain of mountains; in the Americas, commonly applied to the western mountain chain of North and South America.
Core
A long cylindrical piece of rock, about one inch in diameter, recovered by diamond drilling.
Country rock
A general term for the mass of rock surrounding or hosting a mineral deposit; also called host rock.
Crosscut
A horizontal underground opening driven from a shaft or drift approximately perpendicular to the strike of a vein or other mineralized body.
Crust
The outer layer of the Earth, including both continental and oceanic crust.
Cum-dividend
In a share sale, indicates that the buyer is entitled to receive a declared but unpaid dividend.
Current assets
Company assets that can be converted into cash within one year, including cash, marketable securities, accounts receivable and inventories.
Current liabilities
Short-term obligations that a company must pay within one year or within its normal operating cycle.
Custom smelter
A smelter that processes concentrates from independent mines, either by purchasing them or by providing treatment under contract.
Cut-and-fill
A stoping method in which ore is removed in successive cuts and the excavation is filled with waste rock or other material before the next cut is mined.
Cut-off grade
The minimum grade below which material is not included as mineable ore in a resource, reserve or mine plan.
Cyanidation
A method for extracting gold or silver from crushed or ground ore by dissolving it in a dilute cyanide solution. It may be applied in tanks or heaps.
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 that is valid only on the day it is entered.
Debenture
A debt instrument backed only by the issuer's general credit, without a specific lien on a particular asset.
Debt financing
Raising capital by borrowing money from a financial institution or other lender.
Deferred charges
Expenses incurred but not charged to the current year's operations.
Density
Mass per unit volume. In resource estimation it is commonly expressed in tonnes per cubic metre; at smaller scales, in grams per cubic centimetre. Also called specific gravity.
Depletion
An accounting and tax concept that recognizes the progressive exhaustion of a mineral deposit, which is the principal asset of a mine.
Deposit
A rock body containing valuable minerals. The term is usually reserved for mineralized zones whose size and continuity have been evaluated, wholly or partly, by sampling.
Depreciation
A periodic accounting charge that recognizes the loss of value or economic potential of plant and equipment assets.
Development
Underground work carried out to open up a mineral deposit, including sinking shafts, driving crosscuts, drifting and raising.
Development drilling
Drilling intended to define more accurately the geometry, grade and continuity of a deposit for resource or reserve estimation.
Diabase
A basic igneous rock that commonly occurs in dikes or sills.
Diamond
A mineral composed of pure carbon and known for its extreme hardness. Lower-quality diamonds are used to make diamond-drilling bits.
Diamond driller
A person who operates diamond drilling equipment.
Dike
A long, relatively thin tabular body of igneous rock that intruded a fracture in older rocks while molten.
Dilution (mining)
The unavoidable extraction of waste rock with ore during underground mining, usually expressed as the ratio of waste to total material mined in a stope or mine.
Dilution (shares)
A reduction in value per share caused by the issuance of additional shares or options, reducing existing shareholders' relative ownership or earnings per share.
Diorite
An intrusive igneous rock composed mainly of sodic plagioclase, hornblende, biotite or pyroxene.
Dip
The angle at which a vein, structure or bed is inclined from the horizontal, measured perpendicular to its strike.
Dip needle
A compass with a needle mounted to swing in a vertical plane, used to measure magnetic inclination and for prospecting work.
Directional drilling
A drilling method that uses tools such as stabilizers, motors or wedges to control and orient the hole trajectory.
Discounted cash flow
A technique for estimating the value and profitability of a project by discounting expected future cash flows at a specified rate.
Dispersal train
A plume or band of soil, drift or debris generated by mechanical movement of surface material, such as glacial erosion. Mineral trains can lead explorers back to the source of mine...
Disseminated mineralization
Mineralization in which small particles of valuable minerals are distributed more or less uniformly through the host rock.
Dividend
Money or shares distributed to preferred and common shareholders at the discretion of the company's board of directors.
Dividend claim
A claim made when a dividend was paid to the previous holder because the shares had not yet been transferred to the new owner.
Dore bar
The final saleable product of a gold mine, consisting of an impure alloy that generally contains gold and silver.
Drift
A horizontal underground opening driven along the direction of a vein or rock formation, unlike a crosscut, which cuts across the main structure.
Drift-and-fill
A cut-and-fill method in which one drift or slice of the stope is mined at a time, filled, and then mining advances to the next one.
Drill
A machine that drills holes by rotating or percussing a drill string fitted with a bit. It is commonly used for large-diameter blast holes in open-pit mines.
Drill-indicated resource
The potential size and quality of a mineral deposit suggested by widely spaced drilling; additional work is required before it can be classified as probable or proven reserves.
Dry
The mine building where workers change clothes; also called a change house.
Due diligence
Reasonable financial and technical care and investigation carried out before making an investment or acquisition decision.
Electrolysis
A process in which an electric current passes through a solution or melt, causing chemical reactions such as metal deposition on a cathode.
Electrolytic refining
A process for purifying metal ingots suspended as anodes in an electrolytic bath, alternating with refined sheets of the same metal acting as cathodes or starter sheets.
EM survey
A geophysical survey method that measures the electromagnetic properties of rocks.
Emulsion explosives
An explosive mixture containing an aqueous oxidizer solution plus a fuel, such as oil, metal powder or an organic compound, and an emulsifier to prevent separation of the constitue...
En echelon (stepped structures)
A set of stepped, subparallel and partly overlapping structures.
Environmental impact study
A report prepared before a production decision that assesses the potential effects of proposed mining activities on the environment and surrounding area.
Epigenetic
Applied to mineral deposits formed by hydrothermal fluids or gases introduced into pre-existing host rocks. The opposite is syngenetic.
Epithermal deposit
A deposit formed at shallow depth and relatively low temperature, commonly in veins or replacement bodies in volcanic or sedimentary rocks, and often associated with precious metal...
Equity financing
Raising capital by selling or issuing shares of the company.
Erosion
The breakdown, removal and transport of rock or surface material by wind, rain, wave action, freezing, thawing or other natural processes.
Erratic
A fragment transported from its place of origin; it may refer to visible gold in drill core or to a large glacial boulder.
Escarpment
A cliff, scarp or steep slope along the edge of a plateau, mesa or terrace.
Escrowed shares
Shares held in custody or escrow until specified conditions are met, and normally unavailable for trading until released.
Ex-dividend
In a share sale, indicates that the seller retains the right to receive a pending dividend.
Exploration
Prospecting, sampling, mapping, diamond drilling and other work involved in the search for minerals.
Face
The end of a drift, crosscut or stope where work is being carried out.
Fault
A break in the Earth's crust caused by tectonic forces that have moved rock on one side relative to the other.
Feasibility study
A detailed technical and economic study evaluating whether a deposit can be mined profitably, estimating capital investment, operating costs, production and expected revenues.
Feldspar
A common group of rock-forming minerals that includes microcline, orthoclase, plagioclase and other aluminosilicates.
Felsic
A term used to describe light-colored rocks containing feldspar, feldspathoids and silica.
Ferrous
Containing iron.
Fineness
The proportion of pure gold or silver in jewelry or bullion, expressed in parts per thousand; for example, 925 equals 92.5% pure metal.
Fissure
A long crack, split, break or fracture in rock.
Fixed assets
Assets such as buildings, machinery and land that, unlike current assets, are not usually converted into cash during the normal business cycle.
Float
Pieces of rock broken from their original location by natural forces such as frost or glacial action.
Flotation
A concentration process in which selected valuable minerals attach to air bubbles and float while other minerals sink.
Flow sheet
A diagram showing, step by step, the sequence of operations by which ore is treated in milling, concentration or smelting processes.
Flow-through shares
Shares of an exploration company that allow tax deductions or exploration credits to be transferred from the company to the shareholder.
Flux
A chemical substance that reacts with gangue to form liquid slag at furnace temperature, with density low enough to float on the molten metal bath.
Fluxgate magnetometer
A geophysical instrument used to measure the total magnetic field.
Footwall
Rock on the lower side of a vein, fault or mineralized body.
Fossil nodule
A sedimentary concretion containing fossils preserved inside.
Fracture
A break in rock whose opening allows mineralized solutions to enter. A cross joint is a minor fracture extending approximately perpendicular to the main joint direction.
Free-milling
Gold or silver ore from which precious metals can be recovered by conventional concentration methods without pressure leaching or other intensive chemical treatment.
Fully diluted
Based on the maximum number of shares a company could have outstanding, including shares issued through conversion of debt, exercise of rights, warrants or options.
Futures contract
A contract to buy or sell a commodity for delivery on a specified future date under agreed conditions.
Gabbro
A dark, coarse-grained igneous rock.
Galena (lead sulphide)
Lead sulphide, the most common ore mineral of lead.
Gamma (magnetic unit)
A unit of magnetic intensity.
Gangue
Minerals of little or no economic value occurring with the ore.
Geiger counter
An instrument used to measure radioactivity emitted by certain minerals using a Geiger-Mueller tube.
Geochemistry
The study of the chemical properties of rocks.
Geologic era
A major division of geologic time, such as the Precambrian era.
Geology
The science that studies the rocks, materials, structures and history of the Earth.
Geophysical survey
A scientific prospecting method that measures physical properties of rock formations, such as magnetism, specific gravity, electrical conductivity and radioactivity.
Geophysics
The study of the physical properties of rocks, minerals and geological structures.
Geostatistics
A technique used to estimate grades and tonnages of mineral deposits through spatial correlation of data and interpolation between sampled points.
Geothermal
Related to the Earth's internal heat.
Glacial drift
Sedimentary material transported by glaciers.
Glacial striation
A line or scratch on a smoothed rock surface caused by glacial abrasion.
Glory hole
An open excavation from which ore is extracted, especially where broken ore passes to underground workings before being hoisted.
Gneiss
A crystalline metamorphic rock, banded or layered, whose minerals are aligned or elongated in a nearly parallel arrangement.
Gold loan
A form of debt financing in which a potential gold producer borrows gold, sells it in the market to fund mine development, and repays the gold from future production.
Gossan (iron cap)
An iron-oxide cap or stain over a deposit, generally formed by oxidation and alteration of iron sulphides.
Gouge
Fine, putty-like material composed of crushed rock found along a fault.
Grab sample
A sample from a rock outcrop analyzed to determine whether the rock contains valuable elements. It is not intended to be representative, and the apparently best material is usually...
Graben (fault block)
A block of rock down-dropped between normal faults.
Grade
The concentration of a valuable metal or mineral in rock, commonly expressed as a percentage, grams per metric tonne or ounces per ton. It may also refer to concentrate or matte gr...
Granite
A coarse-grained intrusive igneous rock composed of quartz, feldspar and mica.
Gravity meter
An instrument for measuring the Earth's gravitational attraction, which varies with the density of surrounding rocks.
Greenstone belt
An area underlain by metamorphosed volcanic and sedimentary rocks, commonly within a continental shield.
Grey market
A market for securities that are not yet listed on an exchange-traded quotation system.
Grizzly
A grating, usually built from steel rails, placed over the top of a chute or ore pass to retain large blocks of rock or ore that could obstruct the passage.
Gross value
The theoretical value of a mineral or concentrate calculated only from its metal content, without considering costs or recoveries.
Gross value royalty
A share of the gross revenue from mineral sales from a mine.
Grouting
The process of sealing water flows in rock by injecting cement grout or other chemicals into cracks or fractures, usually through drill holes.
Grubstake
Funding, provisions or supplies given to a prospector in exchange for an interest in any discovery made.
Guides
Rails or guides installed along a shaft to stabilize and direct the cage or other conveyance.
Gypsum
A sedimentary rock consisting of hydrated calcium sulphate.
Halite
Rock salt.
Hanging wall
Rock on the upper side of a vein or mineralized body.
Head grade
The average grade of ore fed into a mill.
Headframe
A structure built over a mine shaft to support the hoisting system.
Heap leaching
A process in which valuable metals, usually gold or silver, are leached from a pile of crushed ore by solutions percolating downward and collected on an impermeable base.
Hedge
Taking a buying or selling position in the futures market opposite to a position held in the spot market to reduce the risk of loss from adverse price movements.
Hematite
An iron oxide and one of the most common iron minerals.
High grade
Rich ore. As a verb, it refers to selectively mining the highest-grade ore in a deposit.
High-grader
A person who selectively mines, and often illicitly removes, the richest ore, especially gold.
Holding company
A corporation whose main activity is holding a controlling interest in one or more companies.
Hornfels
A fine-grained contact metamorphic rock.
Horse
A mass of barren rock that interrupts or cuts through a vein or mineral deposit.
Horst
A block of rock bounded by faults and uplifted relative to adjacent blocks.
Host rock
The rock that surrounds or contains a mineral deposit.
Hydrometallurgy
Treatment of ore by wet processes such as leaching a metal and subsequently recovering it from solution.
Hydrothermal
Related to hot fluids circulating in the Earth's crust.
Hypogene
Processes occurring at depth, especially the main hydrothermal processes that formed a mineral deposit.
Igneous rocks
Rocks formed by the solidification of molten material from depth in the Earth.
Ilmenite
A titanium mineral, an iron-titanium oxide.
Incline
An inclined underground opening used for machine access between levels or from surface; also called a ramp.
Income statement
A financial statement summarizing a company's revenues, costs and expenses, and showing the resulting profit or loss.
Indicated resource
A resource whose size and grade have been estimated from sampling sufficiently close-spaced to reasonably assume continuity.
Indicator minerals
Minerals typical of particular rock types or mineral deposits, such as pyrope garnet and chrome diopside in kimberlite. Tracing them to their source can help locate mineral deposit...
Industrial minerals
Non-fuel, non-metallic minerals used by chemical and manufacturing industries, such as asbestos, gypsum, salt, graphite, mica, gravel, building stone and talc.
Inferred resource
A resource whose size and grade are estimated mainly from limited sampling information, assuming continuity of the mineralized body based on geological evidence.
Initial public offering
The first sale of a company's shares to the public, generally underwritten by a group of investment banks or brokers.
Installment receipt
A security representing recently issued shares and requiring additional payments before the final shares are delivered.
Institutional investors
Pension funds, mutual funds and similar organizations that manage money for large numbers of individual investors.
Intermediate rock
An igneous rock with intermediate silica content, approximately 52% to 66%.
Intrusion
A body of igneous rock formed by the consolidation of magma introduced into pre-existing rocks, as distinct from lava, which reaches the surface.
Ion exchange
A process in which certain ions in solution are exchanged for others fixed on a resin or solid. It is used to recover dissolved valuable metals, such as uranium.
Iron ore pellet
An agglomerated ball of iron ore, about marble size, prepared for transport and use in steelmaking.
Jig (gravity concentrator)
A gravity-concentration device that separates minerals on a submerged screen using reciprocating screen motion or pulses of water.
Joint Ore Reserves Committee (JORC)
A code developed by the Australian minerals industry for consistent reporting of mineral resources and ore reserves.
Kimberlite
A variety of peridotite and the most common host rock for diamonds.
Kriging
In geostatistics, a method for estimating grades or values at unsampled points from known data at nearby locations.
Lagging
Small boards or timbers placed between steel sets in the back of a stope or drift to prevent rock falls rather than to carry the main load of overlying rock.
Lamprophyre
An igneous rock composed of dark minerals that commonly occurs in dikes and may, in some cases, be associated with diamonds.
Laterite
A residual soil typical of tropical regions from which much silica has been leached. It may host iron, nickel, cobalt, bauxite or manganese deposits.
Lava (volcanic rock)
The common name for molten rock expelled by volcanoes.
Leachable
Extractable by chemical solvents.
Leaching
A chemical process for extracting valuable minerals from ore; also a natural process in which groundwater dissolves minerals, leaving the rock depleted in some constituents.
Lens
A term used for a mineralized body that is thicker in the middle and tapers toward the ends.
Lenticular deposit
Having the approximate shape of a double-convex lens.
Level
A horizontal opening at a working horizon in a mine. Levels are commonly developed at regular intervals from a shaft or raise.
Lignite
A soft, brownish-black, low-rank coal.
Limestone
A stratified sedimentary rock composed mainly of calcium carbonate.
Limit order
An order given to a broker to buy or sell shares at a specified price or better.
Limonite
A hydrated iron oxide, yellowish brown to brown in color.
Line cutting
Straight openings cut through brush or forest to permit sight lines or geophysical surveys.
Loading pocket
A chamber excavated in rock at the base of an ore pass, where broken ore accumulates before hoisting or transport.
Lode
A mineral deposit in solid rock.
Logging
The process of recording geological observations of drill core, on paper or in digital form.
London Metal Exchange
The London Metal Exchange (LME), the principal market for trading base metals, based in London.
Long ton
A unit of mass equal to 2,240 lb avoirdupois.
Longwall
A mining method in which thin vertical slices of ore or coal are cut along a long working face.
Macrodiamond
A diamond with at least one dimension greater than 0.5 mm, used in exploration to assess diamond potential.
Mafic rocks
Igneous rocks composed mainly of dark minerals rich in iron and magnesium.
Magma (molten rock)
Molten material inside the Earth from which igneous rocks form.
Magmatic segregation
An ore-forming process in which valuable minerals are concentrated by settling or separation during cooling of magma.
Magnetic survey
A geophysical survey that measures the intensity of the Earth's magnetic field.
Magnetic susceptibility
A measure of the ability of a rock or mineral to become magnetized in the presence of a magnetic field.
Magnetite
A black magnetic iron mineral composed of iron oxide.
Magnetometer
An instrument used to measure the magnetic attraction of underlying rocks.
Map staking
A form of claim staking used in some jurisdictions, in which claim boundaries are drawn on official maps at the appropriate government office.
Marble
A metamorphic rock derived from recrystallization of limestone or dolomite under intense heat and pressure.
Margin
Cash deposited with a broker as partial payment for listed securities. The security is held by the broker as collateral for the loan.
Marginal deposit
A mineral deposit with minimal profitability.
Market order
An order to buy or sell at the best available price; if no limit price is specified, it is considered a market order.
Mass spectrometry
An instrumental chemical analysis method that separates and detects atoms or molecules according to mass. It can measure very low concentrations and isotope ratios.
Massive sulphides
A rock body composed mainly or entirely of sulphide minerals such as pyrite, pyrrhotite or chalcopyrite; it may constitute a massive sulphide deposit.
Matte
A molten sulphide product containing metal and sulphur that requires further refining to obtain pure metal.
Measured resource
A resource whose size and grade have been estimated from sampling sufficiently close-spaced to essentially confirm continuity.
Metallurgical coal
Coal suitable for producing coke, used in iron and steelmaking.
Metallurgy
The discipline that studies and applies processes for extracting and treating metals from their ores.
Metamorphic rocks
Rocks whose texture or composition has changed as a result of heat and/or pressure.
Metamorphism
A process by which the texture, mineralogy or structure of rocks changes under heat, pressure or fluids.
Metasomatism
Replacement of pre-existing minerals and addition of new minerals in a rock by introduced material, generally transported by aqueous solutions through fractures and porous zones.
Microdiamond
A diamond with a maximum dimension less than 0.5 mm. It is commonly found in exploration samples and may indicate diamond potential, although not necessarily economic extractabilit...
Micron
Now more correctly called a micrometre. It is one millionth of a metre, equivalent to 0.001 mm, and is commonly used to express grain size.
Microprobe
An analytical instrument that determines the composition of mineral grains or zones within a grain by measuring energy emitted when they are excited by an electron beam.
Migmatite
A mixed rock formed by alternating layers or bands of granitic material and metamorphic material such as schist or gneiss.
Mill
A plant where ore is treated and metals are recovered or products prepared for smelting; it may also refer to a rotating drum used to grind ore.
Mill ore
Ore containing enough valuable mineral to be treated economically by a milling process.
Millivolts
A unit of voltage equal to one thousandth of a volt.
Mine car
A vehicle or car used in a mine to transport ore or waste rock.
Mineable reserves
A redundant term because reserves, by definition, include only the portion of a deposit that is economically mineable.
Mineral (natural substance)
A naturally occurring homogeneous substance with defined physical properties and characteristic chemical composition, which forms crystals under favorable conditions.
Minority interest
The equity interest in a company held by non-controlling shareholders. In subsidiaries, it is the portion of assets or earnings attributable to those shareholders.
Mobile metal ion geochemistry
A geochemical technique in which weakly bound metals transported upward from deep mineral deposits are extracted from soil for analysis.
Muck
Ore or rock broken by blasting.
Muck sample
A representative piece of mineralized material taken from a muck pile and assayed to determine the grade of the pile.
Multispectral exploration
A remote-sensing technique, usually from satellites or aircraft, that records reflected visible and infrared wavelengths from the Earth's surface. It can be used to prepare maps an...
Nanotesla (magnetic unit)
An international unit for measuring magnetic flux density.
National Instrument
In Canadian securities law, a regulation approved by securities regulators in all provinces and adopted by law. National Instrument 43-101 governs disclosure for mineral exploratio...
Native metal
A metal that occurs naturally in pure form, not combined with other elements.
Net asset value
A corporation's total assets minus total liabilities; also called net worth or book value.
Net present value
The calculated value of a project or asset based on estimated future cash flows discounted at a specified rate.
Net profits interest
A share of profit after all charges have been deducted, including taxes and accounting charges such as depreciation.
Net smelter return (NSR)
The gross value of metal contained in ore or concentrate less transportation, smelting and refining charges; also used as a royalty basis.
Neutron activation analysis
An instrumental chemical analysis method in which a sample is irradiated with neutrons, producing radioisotopes of the elements being analyzed. The emitted radiation is measured to...
Norite
A coarse-grained igneous rock that hosts copper-nickel deposits in the Sudbury area of Ontario.
Nugget
A large mass of precious metal found loose in nature.
Nugget effect
Extreme variability caused by the irregular presence of discrete high-value particles such as gold or diamonds, which can distort small-sample results. It is reduced by taking larg...
Odd lot
A lot of shares smaller than a full board lot.
Open order
An order to buy or sell shares that remains in effect until it is cancelled by the client or executed.
Open pit
A mine developed entirely from the surface; also called an open-cast mine.
Open stoping
Mining by removing a relatively large block of ore and allowing the void to remain open while extraction is completed; the stope may be filled later.
Option
An agreement to purchase a property between the property seller and another party that wishes to explore it later.
Ore
Mineralized material from which one or more valuable minerals or metals can be economically extracted.
Ore pass
A vertical or inclined opening used to transfer ore by gravity from one level to a haulage shaft or lower level.
Ore reserves
An estimate of the tonnage and grade of mineralization that can be mined economically, usually classified as proven or probable according to confidence level.
Ore shoot
A local concentration of ore or valuable minerals within a vein or mineralized zone.
Ore shoot (mineralized shoot)
A portion of a vein or other structure containing enough valuable mineral, in grade and continuity, to be mined at a profit.
Orebody
A natural concentration of valuable mineral or minerals that can be extracted and sold at a profit.
Organic maturation
The process of converting peat into coal.
Orogeny
A mountain-building period or process characterized by folding, deformation and uplift of part of the Earth's crust.
Orthogneiss
Gneiss rich in quartz, feldspar and mafic minerals, indicating derivation from an igneous parent rock.
Outcrop
Exposure of rock or a mineral deposit visible at the surface and not covered by soil or water.
Over-the-counter market
A market for securities that are not traded on a formal exchange or through a centralized quotation system.
Overturned
Describes sedimentary beds in which older beds lie above younger beds.
Oxidation
A chemical reaction caused by exposure to oxygen that changes the chemical composition of a mineral.
Oxidation zone
The upper portion of a deposit that has been oxidized by exposure to air and water.
Oxide
A compound of oxygen with another element. Important ores of iron, titanium, manganese and tin include oxides.
Oxide ore
Ore or mineralization in the weathered zone, where sulphide minerals have been transformed into oxides by exposure to air and groundwater.
Panning
Washing gravel, sand or crushed rock samples to separate gold or other valuable minerals using their higher density.
Par value
The stated nominal value of a share. No-par-value shares do not specify one, although total authorized capital is recorded in corporate documents.
Paragneiss
Gneiss derived from sedimentary rock, commonly rich in aluminosilicate minerals such as sillimanite, cordierite or mica.
Participating interest
A company's interest in a mine that entitles it to a percentage of profits in exchange for funding an equivalent percentage of project capital costs.
Passing size
The upper size limit of a particle fraction in mineral processing or metallurgical testing. For example, P80 = 0.1 mm means that 80% of the particles are smaller than 0.1 mm.
Patented claim
The final stage in certain mineral-claim systems, in which mineral rights are fully granted and no further assessment work is required.
Pegmatite
A very coarse-grained igneous rock of generally irregular texture and granitic composition; it commonly occurs in dikes or veins and may contain valuable minerals.
Pentlandite
An iron-nickel sulphide and the most common ore mineral of nickel.
Peridotite
An intrusive igneous rock consisting mainly of olivine.
Permeability
The ability of a rock to transmit fluids such as groundwater. The permeability coefficient, now more correctly called hydraulic conductivity, expresses the volume of water passing ...
Phaneritic
A term used to describe the coarse-grained texture of some igneous rocks.
Pig iron
Crude iron produced in a blast furnace.
Pitchblende
An important uranium mineral, black in color, with a characteristic greasy luster and high radioactivity.
Placer
A deposit of sand and gravel containing valuable minerals or metals, such as gold, tin or diamonds, concentrated by alluvial processes.
Plug
A small, roughly cylindrical or irregular body of intrusive igneous rock associated with a larger intrusive mass.
Plunge
The vertical angle that a geological lineation makes with the horizontal plane. It may also refer to the downward pitch of a deposit measured within the plane of its host structure...
Polishing pond
The last in a series of settling ponds through which mill effluent passes before discharge to the environment.
Polygonal estimate
A resource or reserve estimate calculated from the volume, average grade and average density of polygonal blocks approximating the shape of the mineral deposit.
Pooling shares
See escrowed shares.
Porphyry copper
A disseminated copper deposit in or around a large intrusive rock body.
Portable infrared multispectral analyzer
An instrument that measures infrared radiation reflected from rock sample surfaces or outcrops. Certain minerals reflect specific infrared wavelengths.
Precambrian shield
The oldest and most stable regions of the Earth's crust; the Canadian Shield is a classic example.
Preferred shares
Shares that rank ahead of common shares, but behind bonds, in distributions of earnings or claims on company assets in liquidation. They pay a fixed dividend but normally do not ca...
Price-earnings ratio
The current market price of a share divided by the company's net earnings per share.
Primary deposits
Valuable minerals deposited during the original mineralizing events, as distinct from those formed by later alteration or weathering.
Private placement
The sale of shares to individuals or corporations outside the open market at a negotiated price, often used to finance smaller exploration companies.
Probable reserves
Reserves estimated with a lower level of confidence than proven reserves, but sufficient to support mine planning under accepted technical criteria.
Proton magnetometer
A geophysical instrument that measures total magnetic field intensity.
Proven reserves
Reserves supported by detailed sampling, usually close-spaced diamond drilling and in some cases underground workings, sufficient to estimate grade and tonnage with high confidence...
Proxy
Legal authorization given by a shareholder for another person to vote the shareholder's shares at a meeting.
Pyroclastic rock
Fragmental volcanic rock such as tuff, lapilli tuff, agglomerate or breccia.
Quartz
A common rock-forming mineral composed of silicon dioxide.
Quartzite
A metamorphic rock formed by the transformation of sandstone under heat and pressure.
Radioactivity
The property of certain materials to spontaneously emit alpha, beta or gamma radiation through decay of atomic nuclei.
Radon survey
A geochemical prospecting technique that detects traces of radon gas, a product of radioactive decay.
Raise
A vertical or inclined underground opening excavated upward from a lower level.
Raise borer
A machine that uses a rotary cutting head to enlarge a pilot hole and excavate a raise.
Rare earth elements (REE)
A group of 17 chemical elements made up of the lanthanides plus scandium and yttrium.
Reaming shell
A diamond-set component of the diamond-drilling string placed between the bit and core barrel to maintain the hole diameter.
Reclamation
Restoration of a site after mining or exploration activity has ended.
Reconnaissance
A preliminary study of a region or area.
Record date
The date on which a shareholder must be registered in a company's books to receive a declared dividend or vote on corporate matters.
Recovery
The percentage of valuable metal contained in ore that is recovered by metallurgical treatment.
Recovery factor
The fraction of a reserve or resource that can be effectively extracted during mining.
Refractory ore
Ore that resists normal chemical treatment and requires pressure leaching or other special methods to fully recover valuable minerals.
Regional metamorphism
Metamorphism caused by a combination of heat associated with igneous processes and tectonic pressure on a regional scale.
Regolith
Loose rock material overlying bedrock, either weathered in place or transported by surface processes.
Remote sensing
The use of photographic images or other data captured from aircraft or satellites to map geological structures and surface features.
Replacement ore
Ore formed by replacement, where some minerals were dissolved and removed while valuable minerals were deposited in their place.
Reserve
The part of a mineral resource that can be mined economically under defined technical, economic and legal conditions.
Resource
An estimated quantity of material in a mineral deposit, classified as measured, indicated or inferred according to the density and quality of available information.
Resuing
A narrow-vein stoping method in which the barren rock adjacent to the vein is blasted first, followed by extraction of the ore.
Reverberatory furnace
A long, low furnace used to smelt ore and gangue, produce slag and obtain a metallic or sulphide matte.
Reverse circulation
A drilling method in which a rotating bit breaks rock and cuttings return to surface through reverse circulation of air or fluid. Unlike diamond drilling, it does not recover intac...
Rhyolite
A fine-grained extrusive igneous rock with the same chemical composition as granite.
Rib samples
Samples taken from a safety pillar in a mine to determine metal content.
Rights
Negotiable rights to purchase treasury shares in a specified amount, price and period. Their value is usually related to the underlying share price and their term is shorter than a...
Rock
Any natural combination of minerals; part of the Earth's crust.
Rock bolting
Supporting rock openings with steel bolts installed and anchored in holes drilled for that purpose.
Rock mechanics
The study of the mechanical properties of rocks, including stress conditions around mine workings and the capacity of underground structures to withstand them.
Rockburst
A violent release of energy caused by unexpected failure of walls or pillars in a mine under the weight or pressure of surrounding rock.
Rod mill
A steel cylinder using steel rods as grinding media, fed with crushed ore for size reduction.
Room-and-pillar mining
A method for mining flat-lying deposits in which mined-out rooms are separated by pillars of ore or rock left to support the roof.
Rotary air blast
A rotary drilling method that uses compressed air to carry drill cuttings to the collar of the hole.
Royalty
A periodic payment made by the lessee or operator of a mineral property to the owner or rights holder, commonly based on an amount per tonne or a percentage of production, revenue ...
Run-of-mine ore
Ore as it comes from the mine before crushing, screening or treatment; it commonly represents the average grade of mined material.
Salting
Fraudulent introduction of metals or minerals into a deposit or sample to produce falsely high assay results.
Sample
A small portion of rock or mineral deposit taken to determine metal content by analysis.
Sampling
Selecting a fractional but representative portion of a mineral deposit for analysis.
Sandstone
A sedimentary rock formed from cemented sand grains.
Saprolite
Strongly weathered residual soil formed in place from rock, composed mainly of clay and silt. Further weathering may convert it to laterite, and it commonly occurs between laterite...
Scaling
Removing loose rock from the back and walls of an underground working to prevent falls of ground.
Schist
A foliated metamorphic rock whose platy minerals are arranged approximately parallel, generally due to pressure and deformation.
Schistosity
The foliation characteristic of schists, produced by the preferred orientation of platy or elongated minerals.
Scintillometer
An instrument used to detect and measure radioactivity by detecting gamma rays. It is more sensitive than a Geiger counter.
Scoping study
A preliminary economic study of a mining project used for early planning. It is based on assumptions and estimated costs and does not have the detail or reliability of a feasibilit...
Screen size
A system for expressing particle sizes according to standard wire-mesh screen openings. A 200-mesh screen equals 0.074 mm; as a rough rule, 15 divided by the mesh number gives part...
Secondary enrichment
Enrichment of a vein or deposit by minerals dissolved, moved by solutions and redeposited elsewhere in the mineralized body or adjacent rocks.
Sedimentary rocks
Rocks formed from material derived from other rocks and deposited, generally under water. Examples include limestone, shale and sandstone.
Self-potential
A geophysical prospecting technique that detects and measures natural electrical currents generated by certain sulphide deposits.
Semi-autogenous grinding (SAG)
A grinding method in which the grinding medium consists of large ore fragments together with steel balls.
Semivariogram
In geostatistics, a graph or function describing the variation of a variable with distance and used to evaluate spatial continuity in a deposit.
Serpentine
A greenish metamorphic mineral composed of magnesium silicate.
Shale
A sedimentary rock formed by consolidation of mud or silt.
Shear
Rock deformation by lateral movement along numerous approximately parallel planes, generally caused by tectonic stress and associated with cleavage or schistosity.
Shear zone
A zone in which large-scale shearing has occurred.
Sheave wheel
A grooved wheel at the top of a headframe over which the hoisting rope passes.
Short sale
The sale of borrowed shares with the expectation of buying them back later at a lower price.
Short ton
A unit of mass equal to 2,000 lb avoirdupois.
Showing
A localized mineral occurrence whose extent or continuity is not yet known.
Silt
Fine sediment, intermediate in size between sand and clay, commonly deposited in low-energy environments such as lake bottoms or floodplains.
Sinter
Fine iron ore particles thermally treated to produce suitable blast-furnace feed.
Skarn (contact rock)
A contact metamorphic rock formed when an igneous intrusion interacts with carbonate rocks such as limestone or dolomite.
Skip
A self-dumping bucket used in a shaft to hoist ore or rock.
Slag
A glassy mass separated from molten metals during smelting.
Slashing
Blasting rock from the side of an underground opening to widen it.
Slickenside
A polished and striated fault surface produced by one rock block rubbing against another.
Sludge
Fine mud or detritus generated during diamond drilling, sometimes used for studies or sampling.
Sodium cyanide
A chemical used in milling gold ores to dissolve gold and silver.
Solvent extraction-electrowinning (SX-EW)
A hydrometallurgical process used mainly for copper, in which metal is leached, concentrated with organic solvents and recovered by electrowinning.
Specific gravity
Density.
Spelter
Commercial zinc of relatively impure grade, cast into slabs or ingots from molten metal.
Sphalerite
A zinc sulphide mineral and the most common ore mineral of zinc.
Station
An enlargement or chamber developed in a shaft to store and handle equipment, or to operate at a particular level.
Step-out drilling
Drilling carried out to test the expected continuation of a mineralized horizon or structure, laterally or down dip.
Stock exchange
An organized market for buying and selling shares, securities and options through authorized intermediaries.
Stock option
The right to buy or sell a share at a fixed price, regardless of the prevailing market price.
Stock split
A shareholder-approved division that converts outstanding common shares into a larger number of new common shares. The opposite is a share consolidation.
Stockwork
A zone of veinlets, stringers and mineralized fractures forming an irregular network; common around intrusions and in some massive sulphide deposits.
Stop-loss order
An instruction to a broker to sell a share if its price falls to a specified level.
Stope
An excavation in a mine from which ore has been, or is being, extracted.
Stope face
A working face in a mine, usually restricted to a stope or bench.
Stratification
The arrangement of sedimentary rocks in layers.
Stratigraphy
Strictly, the description of sequences of stratified rocks; commonly used for the sequence of stratified rocks in a particular area.
Streak
A diagnostic mineral property consisting of the color of the powder left when the mineral is rubbed on an unglazed porcelain plate.
Street certificate (share certificate)
A share certificate registered in the name of a previous owner and endorsed for transfer to a new owner without involvement of the transfer agent.
Striations
Prominent parallel scratches left on bedrock by the abrasive action of moving glaciers.
Strike
The direction or bearing, relative to true north, of a vein or rock formation measured on a horizontal surface.
Stringer
A thin veinlet or irregular filament of mineral cutting across a rock mass.
Strip mining
A surface mining method, common in coal, in which overburden is removed, the mineralized seam is extracted and the removed material is then replaced or managed.
Stripping
Removing overburden or waste rock overlying a deposit to prepare it for open-pit mining.
Subbituminous coal
A black coal intermediate in rank between lignite and bituminous coal.
Sublevel
An intermediate level or working horizon located between main levels in a mine.
Subsidiary company
A company in which another company owns the majority of voting shares, giving it a controlling position.
Sulphide
A compound of sulphur with another element. The most common base-metal minerals are sulphides.
Sulphide ore
Ore composed mainly of sulphide minerals. In gold deposits in tropical or arid regions, it commonly represents primary, unweathered ore below the oxidized zone.
Sulphur dioxide
A gas released during the smelting of sulphide ores; it may be converted into sulphuric acid or emitted to the atmosphere if not captured.
Sulphur dust explosions
An underground mining hazard associated with combustion or explosion of fine sulphur or sulphide-mineral particles suspended in air.
Sump
An underground excavation where water accumulates before being pumped to surface.
Supergene
A process occurring near the Earth's surface.
Supergene enrichment
A process by which mineralization is enriched through groundwater circulation and weathering; important in certain gold, copper and iron-oxide deposits.
Sustainable development
Industrial development that meets present needs without compromising the ability of the natural environment to benefit future generations.
Synform
A fold similar to a syncline, but in which the relative ages of the folded rocks are unknown.
Syngenetic
A term describing mineralization formed at the same time as the host rocks. The opposite is epigenetic.
Taconite
A hard, abrasive, low-grade siliceous iron formation mined as a source of iron after beneficiation and concentration.
Tailings
Material rejected from a mill after most recoverable valuable minerals have been extracted.
Tailings pond
An impoundment or deposit designed to contain tailings, allow solids to settle and facilitate treatment or degradation of reagents before water is discharged or recycled.
Talus
An accumulation of coarse rock fragments at the base of a steep slope or mountain.
Telluride
A chemical compound consisting of tellurium and another element, often gold or silver.
Thickener
A large, usually circular tank used in processing plants to separate solids from liquids: clarified liquid overflows and solids settle to the bottom.
Tonnage factor
The number of cubic metres of a particular rock type required to obtain one tonne of material. It is the reciprocal of bulk density or specific gravity in compatible units.
Tonne
A metric tonne, equal to 1,000 kilograms.
Tonne unit
In metallurgy, a mass unit equal to one percent of a tonne. A short-ton unit is 20 lb, a long-ton unit is 22.4 lb and a metric-tonne unit is 10 kg.
Tonnes per vertical metre
A unit used to describe the amount of ore per vertical metre of depth in a deposit. It is calculated by multiplying length and width of the mineralized body and dividing by the app...
Treasury shares
Shares authorized but not issued, held in a company's treasury.
Trench
A long, narrow excavation opened in overburden or rock to expose a vein, structure or mineralized zone.
Tube mill
A rotating cylindrical mill, partly filled with steel rods or balls, into which crushed ore is fed for fine grinding.
Tuff
A pyroclastic rock composed of consolidated fine volcanic ash.
Tunnel
A horizontal underground opening open to the atmosphere at both ends.
Umpire assay
An assay performed by an independent third party to resolve differences between buyers and sellers of ore or concentrate.
Uncut value
The actual assay value of a core or sample before reducing it by a cutting or capping formula.
Underhand cut-and-fill
A cut-and-fill mining method in which cemented fill is placed above the working area. It is especially suited to poor ground conditions.
Unlisted
A share not traded on a recognized stock exchange or quotation system.
Uraninite
A uranium mineral with high uranium oxide content, frequently found in pegmatite dikes.
Uranium
A radioactive metallic element, silvery white in color.
Vein
A crack, fault or fissure filled with minerals precipitated from fluids that circulated through the rock.
Vendor
The party that sells a property. In mining, consideration for acquired properties often includes treasury shares that may be escrowed or subject to restrictions.
Visible gold
Native gold visible to the naked eye in a hand specimen.
Volcanic rocks
Igneous rocks formed from magma that flowed out or was violently ejected from a volcano.
Volcanogenic
A term used to describe the volcanic origin of mineralization.
Voting right
A shareholder's right to vote on company matters. Common shares usually carry one vote each; preferred shares may gain voting rights if preferred dividend obligations are not met.
Vug
A small cavity in rock, often lined with well-formed crystals. Amethyst commonly forms in such cavities.
Wall rocks
Rocks on either side of a vein or mineralized body, including the hanging wall and footwall.
Waste dump
A surface pile of waste rock, mine waste or broken mineralized material.
Water gel
A gel-type explosive containing an aqueous oxidizer solution, usually ammonium nitrate, combined with a fuel or sensitizing explosive.
Weathering
Destruction or alteration of primary minerals in a rock by physical, chemical or biological processes at the Earth's surface.
Wedge
A technique used to deflect a diamond drill hole and direct it into a different orientation from its original path.
Work index
The amount of energy required to crush or grind a material to a specified grain size, generally expressed in kilowatt-hours per metric tonne.
Working capital
Liquid resources available to cover daily operating expenses; current assets less current liabilities.
Xenolith
A fragment of country rock incorporated into an intrusive igneous rock.
Yield
The current annual dividend expressed as a percentage of the current market price of the share.
Zone
A distinct area of mineralization.