MINING GLOSSARY

A horizontal passage from the surface into a mine. Sometimes called a tunnel.

A geological feature, esp. in the subsurface, distinguished by geological, geophysical, or geochemical means, which is different from the general surroundings and is often of potential economic value, and usually suggests the possibility of a mineral deposit.

Pertaining to clay or clay minerals; e.g. "argillic alteration" in which certain minerals of a rock are converted to minerals of the clay group.

A tin-white or silver-white to steel-gray mineral. Arsenopyrite occurs chiefly in crystalline rocks and esp. in lead and silver veins, and constitutes the principal ore of arsenic.

As verb: To analyze the proportions of metals in an ore, to test an ore or mineral for composition, purity, weight, or other properties of commercial interest.

The process of refilling an excavation, a mine opening, or the space around a foundation.

A rotating horizontal cylinder with a diameter almost equal to the length supported by a frame or shaft, in which nonmetallic materials are ground using various types of grinding media such as quartz pebbles, porcelain balls, etc.

Any of the more common and more chemically active metals, e.g. lead, copper.

The principal metal of an alloy, e.g. the copper in brass.

Perhaps the most common term in geology, meaning layer or stratum. Quarrymen usually mean by beds not the stone beds in the geologist's sense but the partings between them.

A distance below the surface elevation of a shaft.

In an underground mine, a long horizontal face or ledge of ore in a stope or working place.

The horizontal step or floor along which coal, ore, stone, or overburden is worked or quarried.

A hole drilled in a material to be blasted, for the purpose of containing an explosive charge.

A course-grained clastic rock, composed of angular broken rock fragments held together by a mineral cement or in a fine-grained matrix. The fragments have sharp edges and unworn corners.

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

A metamorphic rock consisting mainly of calcium-bearing silicates such as diopside and wollastonite, and formed by metamorphism of impure limestone or dolomite.

Assets, purchased as a long term investment for generating profit, such as buildings, plant and machinery and fixtures etc.

Any vertical cylindrical vessels used to contain granules of activated carbon for processes such as the extraction of gold from solution, elution or acid treatment.

Said of a rock or sediment that is rich in carbon; coaly.

Said of a sediment containing organic matter.

A mineral compound characterized by a fundamental anionic structure.

A sediment formed by the organic or inorganic precipitation from aqueous solution of carbonates of calcium, magnesium, or iron; e.g. limestone and dolomite.

A recovery process in which a slurry of gold ore, carbon granules and cyanide are mixed together. The cyanide dissolves the gold content and the gold is adsorbed on the carbon: the carbon is subsequently separated from the slurry for further gold removal.

A precious metals leaching technique in which granular activated carbon particles much larger than the ground ore particles are added to the cyanidation pulp after the precious metals have been solubilized. The activated carbon and pulp are agitated together to enable the solubilized precious metals to become adsorbed onto the activated carbon. The loaded activated carbon is mechanically screened to separate it from the barren ore pulp and processed to remove the precious metals and prepare it for reuse. Similar to carbon-in-leach process.

Include site costs for all mining (excluding deferred stripping costs), processing and administration, but are exclusive of royalties, production taxes, depreciation, reclamation, financing costs, capital costs and exploration costs.

A bright brass-yellow tetragonal mineral. It is generally found massive and constitutes the most important ore of copper.

The total thickness of all reef bands, including internal waste mined as one unit.

The mouth or upper end of a mineshaft.

A system of forces or stresses that tends to decrease the volume or to shorten a substance, or the change of volume produced by such a system of forces.

The valuable fraction of an ore that is left after worthless material is removed in processing.

A plant where ore is separated into values (concentrates) and rejects (tails). An appliance in such a plant, e.g., flotation cell, jig, electromagnet, shaking table. Also called mill; reduction works; cleaning plant.

An apparatus in which, by the aid of water, air, and/or gravity, mechanical concentration of ores is performed.

The total gold content of the orebody (tons multiplied by grade), irrespective of economic potential and without deduction for mining and processing losses prior to recovery.

Represents ounces in the ground without the reduction of ounces not recovered by the applicable metallurgical process.

Contango on gold is the positive difference between the spot market gold price and the forward market gold price. It is often expressed as an interest rate and is the difference between inter-bank deposit rates and gold lending rates.

Any hole drilled for the purpose of obtaining cores.

A stoping method in which the ore is excavated by successive flat or inclined slices, working upward from the level. However, after each slice is blasted down, all broken ore is removed, and the stope is filled with waste (backfill) up to within a few feet of the back before the next slice is taken out, just enough room being left between the top of the waste pile and the back of the stope to provide working space. The term cut-and-fill stoping implies a definite and characteristic sequence of operations:

breaking a slice of ore from the back;

removing the broken ore; and introducing filling.

The lowest grade of mineralized material that qualifies as ore in a given deposit; ore of the lowest assay value that is included in an ore estimate.

A process of extracting gold and silver as cyanide slimes from their ores by treatment with dilute solutions of potassium cyanide or sodium cyanide. The slimes are subsequently fused and cast into ingots or bullion.

Mining costs associated with waste rock removal that are deferred and charged to income on the basis of the average stripping ratio for the mine. The average stripping ratio is calculated as a ratio of the tons of material estimated to be mined to the estimated recoverable ounces of gold. At the start of a mine's productive life costs on a per-ounce basis are usually higher than in later years as the mining rate is above the life-of-mine stripping ratio. In later years, as the mining rate falls below the life-of-mine stripping ratio, the deferred costs are charged to operating costs.

The decrease in quantity of ore in a deposit or property resulting from extraction or production.

The decrease in quantity of ore in a deposit or property resulting from extraction or production.

The preparation of a mining property or area so that an orebody can be analyzed and its tonnage and quality estimates have been made; ore essentially ready for mining.

A variety of rotary drilling in which diamond bits are used as the rock-cutting tool. It is a common method of prospecting for mineral deposits, esp. in development work where core samples are desired.

A tabular igneous intrusion that cuts across the bedding or foliation of the country rock.

A group of dikes, which may be in radial, parallel, or en echelon arrangement. Their relationship with the parent plutonic body may not be directly observable.

The contamination of ore with barren wall rock in stoping. The assay of the ore after mining is frequently 10% lower than when sampled in place.

An igneous rock formed by the solidification of molten material.

Said of a mineral deposit (esp. of metals) in which the desired minerals occur as scattered particles in the rock, but in sufficient quantity to make the deposit an ore.

Gold and silver bullion that remains in a cupelling furnace after the lead has been oxidized and skimmed off.

A horizontal or nearly horizontal underground opening driven along a vein to gain access to the deposit.

Dewatering tailings to higher degrees than a paste consistency. This produces a dry (unsaturated) cake that can no longer be transported by pipeline due to its low moisture content. This method of storing tailings is considered to reduce the environmental impacts.

A process of recovering gold from solution by means of electrolytic chemical reaction into a form that can be smelted easily into gold bars.

A naturally occurring, deep-yellow to pale-yellow alloy of gold with silver; argentiferous gold, containing more than 20% silver.

Recovery of the gold from the activated carbon into solution before zinc precipitation or electro-winning.

The group of physical and chemical processes by which earth or rock material is loosened or dissolved and removed from any part of the Earth's surface. It includes the processes of weathering, solution, corrosion, and transportation.

The process of mining and removal of coal or ore from a mine.

The process of dissolving and separating out specific constituents of a sample by treatment with solvents specific for those constituents.

Soft, un-cemented pulverized clay or claylike material, commonly a mixture of minerals in finely divided form, found along some faults or between the walls of a fault, and filling or partly filling a fault zone; a slippery mud that coats the fault surface or cements the fault breccia. It is formed by the crushing and grinding of rock material as the fault developed, as well as by subsequent decomposition and alteration caused by underground circulating solutions.

A fault that is expressed as a zone of numerous small fractures or of breccia or fault gouge. A fault zone may be as wide as hundreds of meters.

Man-made deposits of natural earth materials (e.g. rock, soil, gravel) and waste materials (e.g. tailings or spoil from dredging), used to fill an enclosed space such as an old stope or chamber in a mine.

A process by which some mineral particles are induced to become attached to bubbles and float, and other particles to sink, so that the valuable minerals are concentrated and separated from the worthless gangue.

The wall or the rock on the underside of a vein or ore deposit.

A general term for debris transported by glaciers or icebergs, and deposited directly on land or in the sea.

The formation, movement, and recession of glaciers or ice sheets.

The covering of large land areas by glaciers or ice sheets.

The geographic distribution of glaciers and ice sheets.

A collective term for the geologic processes of glacial activity, including erosion and deposition, and the resulting effects of such action on the Earth's surface.

Any of several minor parts of geologic time during which glaciers were more extensive than at present.

Gold equivalent ounces include silver ounces produced and sold, converted to a gold equivalent based on a ratio of the average spot market price for the commodities for each year.

The amount of valuable mineral in each ton of ore, expressed as troy ounces per ton or grams per tonne for precious metals and as a percentage for other metals.

A method by which mineral particles are separated with the aid of water or air, according to the differences in their specific gravities.

Size reduction of ore into fine particles to prepare it for processing; comminution.

The overlying side of an orebody, fault, or mine working, esp. the wall rock above an inclined vein or fault.

A large impermeable foundation or pad used as a base for ore during heap leaching.

A process used for the recovery of copper, uranium, and precious metals from weathered low-grade ore. The crushed material is laid on a slightly sloping, impervious pad and uniformly leached by the percolation of the leach liquor trickling through the beds by gravity to ponds. The metals are recovered by conventional methods from the solution.

One hectare = 2.47 acres.

The machine used for raising and lowering the cage or other conveyance in a shaft.

The rock surrounding an ore deposit.

Of or pertaining to hot water, to the action of hot water, or to the products of this action, such as a mineral deposit precipitated from a hot aqueous solution, with or without demonstrable association with igneous processes; also, said of the solution itself.

Said of a rock that does not permit the passage of fluids under the pressure conditions ordinarily found in the subsurface.

Reserves still in the ground

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

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

Diamond drilling at shorter intervals between existing holes, used to provide greater geological detail and to help establish reserve estimates.

That portion included between two points in a borehole, as between the point where the hole first encounters a specific rock or mineral body and where the hole enters a different or underlying rock formation.

One kilometer = 0.62 miles.

The separation, selective removal, or dissolving-out of soluble constituents from a rock or orebody by the natural action of percolating water, or the extraction of soluble metals or salts from an ore by means of slowly percolating solutions.

Number of years that the operation is planning to mine and treat ore, and is taken from the current mine plan.

A mineral deposit consisting of a zone of veins, veinlets, disseminations, or planar breccias; a mineral deposit in consolidated rock as opposed to a placer deposit.

A method of mining involving the drilling of holes up to 90 feet long into an orebody and then blasting a slice of rock which falls into an open space. The broken rock is extracted and the resulting open chamber is not filled with supporting material.

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

Removal of gold and silver from pregnant cyanide solution by de-oxygenation, followed by precipitation on zinc dust, followed by filtration to recover the resultant auriferous gold and silver slimes.

A processing plant erected to treat ore and extract gold

The science and art of separating metals and metallic minerals from their ores by mechanical and chemical processes; the preparation of more metalliferous materials from raw ore.

One meter = 3.28 feet.

A plant where ore is ground fine and undergoes physical or chemical treatment to extract the valuable metals.

The grade of ore as it comes from a mine and goes to a mill.

The combination of various processes and systems which concentrate the valuable minerals.

An excavation beneath the surface of the ground from which mineral matter of value is extracted.

A mineralized body which has been delineated by appropriately spaced drilling and/or underground sampling to support a sufficient tonnage and average grade of metal. This material or deposit does not qualify as a reserve until a comprehensive evaluation, based on costs, grade, recoveries and other factors, demonstrates economic feasibility. Consequently, although the potential exists, there is no assurance that this mineral deposit will ever become an ore reserve.

A mineral resource is a concentration or occurrence of material of economic interest in or on the earth's crust in such form, quality and quantity that there are reasonable and realistic prospects for eventual economic extraction. The location, quantity, grade, continuity and other geological characteristics of a mineral resource are known, estimated from specific geological evidence and knowledge, or interpreted from a well-constrained and portrayed geological model. Mineral resources are subdivided, in order of increasing geological confidence, into inferred, indicated and measured categories. The mineral resources are inclusive of those resources which have been modified to produce ore reserves.

The process or processes by which mineral or minerals are introduced into a rock, resulting in a valuable or potentially valuable deposit.

Mineralized material is the projection of mineralization in rock based on geological evidence and assumed continuity. It may or may not be supported by sampling but is supported by geological, geochemical, geophysical or other data. This material may or may not have economically recoverable mineralization.

That portion of public mineral lands which a party has staked or marked out in accordance with federal, provincial or state mining laws to acquire the right to explore for and exploit the minerals under the surface.

A royalty based on a percentage of gold produced with settlement made either in kind or in currency based on the spot gold sale proceeds received less the cost of refining at an off-site refinery.

Rock, generally containing metallic or non-metallic minerals that can be mined and processed at a profit. Also, the mineral(s) thus extracted.

An elongated pipelike, ribbonlike, or chimneylike mass of ore within a deposit (usually a vein), representing the more valuable part of the deposit.

The fine carbonaceous discharge from a mine washery. All washeries produce some slurry, which must be treated to separate the solids from the water in order to have a clear effluent for reuse or discharge.

A sufficiently large amount of ore that can be mined economically.

A measure of weight in which precious metals are sold, derived from imperial statistics. A troy ounce is equal to 31.1035 grams. A kilogram contains 32.1507 ounces.

Barren rock material, either loose or consolidated overlying a mineral deposit, which must be removed prior to mining.

Mineralized rock in which some of the original minerals have been oxidized. Oxidation tends to make the ore more porous and permits a more complete permeation of cyanide solutions so that minute particles of gold in the interior of the minerals will be readily dissolved

An area of mineral deposits modified by surface waters, e.g. sulfides altered to oxides and carbonates.

A process established under the U.S. General Mining Law of 1872 which permits the conversion of mining claims on federal lands into full fee ownership, provided certain conditions are met.

Pertaining to a rock or soil having a texture that permits passage of liquids or gases under the pressure ordinarily found in earth materials.

Pond containing solution which has percolated through the ore on a heap leach. The solution is impregnated with gold and silver removed from the ore.

Material for which tonnage and grade are computed partly from specific measurements, samples or production data and partly from projection for a reasonable distance on geological evidence; and for which the sites available for inspection, measurement and sampling are too widely or otherwise inappropriately spaced to outline the material completely or to establish its grade throughout.

Material for which tonnage and grade are computed from dimensions revealed in outcrops, trenches, underground workings or drill holes; grade is computed from the results of adequate sampling; and the sites for inspection, sampling and measurement are so spaced and the geological character so well-defined that size, shape and mineral content are established.

A common, pale-bronze or brass-yellow, isometric mineral. It is dimorphous with marcasite, and often contains small amounts of other metals. Pyrite has a brilliant metallic luster and an absence of cleavage, and has been mistaken for gold. Pyrite is the most wide-spread and abundant of the sulfide minerals and occurs in all kinds of rocks, such as in nodules in sedimentary rocks and coal seams or as a common vein material associated with many different minerals.

Crystalline silica, an important rock-forming mineral. It is, next to feldspar, the commonest mineral, occurring either in transparent hexagonal crystals (colorless, or colored by impurities) or in crystalline or cryptocrystalline masses. Quartz is the commonest gangue mineral of ore deposits, forms the major proportion of most sands, and has a widespread distribution in igneous, metamorphic, and sedimentary rocks.

A general term for a variety of non-crystalline or cryptocrystalline minerals having the same chemical composition as that of quartz, such as chalcedony, agate, and opal.

A granoblastic metamorphic rock consisting mainly of quartz and formed by recrystallization of sandstone or chert by either regional or thermal metamorphism.

A very hard but un-metamorphosed sandstone, consisting chiefly of quartz grains that have been so completely and solidly cemented with secondary silica that the rock braks across or though the grains rather than around them. The cement grows in optical and crystallographic continuity around each quartz grain, thereby tightly interlocking the grains as the original pore spaces are filled.

A vertical hole between mine levels used to move ore or waste rock or to provide ventilation.

An inclined underground tunnel which provides access for exploration or a connection between levels of a mine.

The process by which lands disturbed as a result of mining activity are reclaimed back to a beneficial land use. Reclamation activity includes the removal of buildings, equipment, machinery and other physical remnants of mining, closure of tailings impoundments, leach pads and other mine features, and contouring, covering and re-vegetation of waste rock piles and other disturbed areas.

Actual metal content of ore determined after processing.

A term used in process metallurgy to indicate the proportion of valuable material obtained in the processing of an ore. It is generally stated as a percentage of valuable metal in the ore that is recovered compared to the total valuable metal present in the ore.

A term used in process metallurgy to indicate the proportion of valuable material obtained in the processing of an ore. It is generally stated as a percentage of the material recovered compared to the total material present.

A gold-bearing sedimentary horizon, normally a conglomerate ban, that may contain economic levels of gold.

The final stage of metal production in which impurities are removed from the molten metal.

Gold mineralized material in which the gold is not amenable to recover by conventional cyanide methods without any pretreatment. The refractory nature can be either silica or sulphide encapsulation of the gold or the presence of naturally occurring carbons which reduce gold recovery. Material of this nature is difficult or expensive to recover its valuable constituents.

The process of reclaiming land disturbed by mining to allow an appropriate post-mining use and address among other issues, ground and surface water, topsoil, final slope gradient, waste handling and re-vegetation issues.

The quantity of mineral that is calculated to lie within given boundaries. It is described as total (or gross), workable, or probable working, depending on the application of certain arbitrary limits in respect of deposit thickness, depth, quality, geological conditions, and contemporary economic factors. Proved, probable, and possible reserves are other terms used in general mining practice.

That part of a mineral deposit which could be economically and legally extracted or produced at the time of the reserve determination. Reserves are customarily stated in terms of ore when dealing with metalliferous minerals. There are two categories of reserves: Proven Ore & Probable Ore.

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

Drilling that produces rock chips rather than core. Faster and cheaper than diamond drilling, the chips are forced by air to surface for examination.

Holes drilled using a process where the circulation of bit-coolant and cuttings-removal liquids, drilling fluid, mud or air down the borehole outside the drill rods and upward inside the drill rods. Also called countercurrent; counter flush.

A group of extrusive, igneous rocks.

These are types of circular grinding mills used to break the ore down into fine particles in preparation for dissolving out the gold by means of cyanide.

Solid fragmental material that originates from weathering of rocks and is transported or deposited by air, water, or ice, or that accumulates by other natural agents, such as chemical precipitation from solution or secretion by organisms, and that forms in layers on the Earth's surface at ordinary temperatures in a loose, unconsolidated form; e.g., sand, gravel, silt, mud, alluvium.

Rocks formed from material derived generally by erosion of other rocks and laid down by a chemical or mechanical process i.e., limestone, shale and sandstone

A vertical passageway to an underground mine for moving personnel, equipment, supplies and material including ore and waste rock.

A group of closely spaced, distinct parallel fractures filled with mineral matter and separated by layers of barren rock.

A mixture made of course aggregate, applied by pneumatic pressure through a specially adapted hose and used as a fireproofing agent and as a sealing agent to prevent weathering of mine timbers and roadways.

A mixture of crushed and finely ground solids with water.

A metallurgical operation in which metal is separated from impurities by a process that includes fusion.

The use of one or just a few roof bolts at spot locations.

Broken ore heaped on surface or prepared areas underground, pending treatment or shipment.

A mineral deposit consisting of a three-dimensional network of planar to irregular veinlets spaced closely enough that the whole mass can be mined.

An area in an underground mine where ore is mined.

The process of mining the orebody on the plane of the reef.

The sum of the channel width and external waste widths.

A bed or layer of rock; strata, more than one layer.

A fault whose strike is parallel to the strike of the strata.

The longest horizontal dimension of an orebody or zone of mineralization.

The ratio of the number of tonnes of waste material removed to the number of tonnes of ore removed, used in connection with open pit mining.

A sub-group of refractory ore - mineralized rock in which much of the gold is encapsulated in sulphides and is not readily amenable to dissolution by cyanide solutions - associated with sulphide minerals (primarily pyrite) that have not been oxidized. Some sulphide ore may require autoclaving or roasting prior to cyanidation.

Formed contemporaneously with the deposition of the sediment.

The material that remains after all metals considered economic have been removed from ore during milling.

A natural or man-made area suitable for depositing the material that remains after the treatment of ore.

The process of heating activated carbon granules typically to 750 degrees Celsius to restore the properties of carbon for the next gold extraction cycle.

A vessel or apparatus for reducing the proportion of water in a pulp by means of sedimentation.

A period of structural compression in geological time with the generation of low-angle thrust faults.

Imperial unit of weight equal to 2,000 pounds or to 907.185 kilograms.

Quantities where the ton or tonne is an appropriate unit of measure. Typically used to measure resources and reserves of gold-bearing material in situ or quantities of ore and waste material mined, transported or milled.

Metric unit of weight equal to 1,000 kilograms or 2,205 pounds.

Total cash production costs calculated in accordance with the Gold Institute Standard includes direct mining expenses, mine development adjustments, refining and transportation costs, by-product credits, royalties and production taxes.

Total production costs comprise total cash production cost plus depreciation, depletion and reclamation provisions.

(Used in imperial statistics) Equal to 31,10348 grams.

Material that contains insufficient mineralization for consideration for future treatment and, as such, is discarded.

Zinc precipitation is the chemical reaction using zinc dust that converts gold solution to a solid form for smelting into unrefined gold bars.