Great List of Useful Mining / Geological Glossary Terms

Airborne survey - A survey made from an aircraft to obtain photographs, or measure magnetic properties, radioactivity, etc.

Alloy - A compound of two or more metals.

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

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

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

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

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

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

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

Basic rocks - Igneous rocks that are relatively low in silica and composed mostly of dark-colored miner

als.

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

Bedding - The arrangement of sedimentary rocks in layers.

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

Bulk sample - A large sample of mineralized rock, frequently hundreds of tonnes, selected in such a manner as to be representative of the potential orebody being sampled. Used to determine metallurgical characteristics.

Bullion - Metal formed into bars or ingots.

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

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

Capitalization - A financial term used to describe the value financial markets put on a company. Determined by multiplying the number of outstanding shares of a company by the current stock price.

Cesium magnetometer - An geophysical instrument which measures magnetic field strength in terms of vertical gradient and total field.

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

Chalcopyrite - A sulphide mineral of copper and iron; the most important ore mineral of copper.

Chip sample - A method of sampling a rock exposure whereby a regular series of small chips of rock is broken off along a line across the face.

Chromite - The chief ore mineral of chromium.

Claim - A portion of land held either by a prospector or a mining company. In Canada, the common size is 1,320 ft. (about 400 m) square, or 40 acres (about 16 ha).

Clay - A fine-grained material composed of hydrous aluminum silicates.

Complex ore - An ore containing a number of minerals of economic value. The term often implies that there are metallurgical difficulties in liberating and separating the valuable metals.

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

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

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

Cyanidation - A method of extracting exposed gold or silver grains from crushed or ground ore by dissolving it in a weak cyanide solution. May be carried out in tanks inside a mill or in heaps of ore out of doors.

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

Development - Underground work carried out for the purpose of opening up a mineral deposit. Includes shaft sinking, crosscutting, drifting and raising, stripping/open pit mining.

Development drilling - drilling to establish accurate estimates of mineral reserves.

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

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

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

Drill - There are various types of drills for exploration such as a diamond drill (produces core) or reverse circulation drill (produces chips). Other types of drills are used in the mining process which do not produce a core, but are used to make circular holes in the rock which are filled with explosives.

Drill-indicated reserves - The size and quality of a potential orebody as suggested by widely spaced drillholes; more work is required before reserves can be classified as probable or proven.

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

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

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

Exploration - Prospecting, sampling, mapping, diamond drilling and other work involved in searching for ore.

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

Ferrous - Containing iron

Flow-through shares - Shares in an exploration company that allow the tax deduction or credits for mineral exploration to be passed to the investor.

Gabbro - A dark, coarse-grained igneous rock.

Geiger counter - An instrument used to measure the radioactivity that emanates from certain minerals by means of a Geiger-Mueller tube.

Geophysical survey - A scientific method of prospecting that measures the physical properties of rock formations. Common properties investigated include magnetism, specific gravity, electrical conductivity and radioactivity.

Geophysics - The use of geophysical techniques to search for mineral deposits. Common geophysical surveys include: magnetic, electromagnetic, induced polarization, resistivity and gravity

Geothermal - Pertains to the heat of the Earth's interior.

Grab sample - A sample from a rock outcrop that is assayed to determine if valuable elements are contained in the rock. A grab sample will not provide a representative picture of the value of a deposit, only an indication.

Grade - The value of a mineralized deposit. Precious metals are usually expressed as ounces per tonne or grams per tonne. Base metals and uranium are expressed as a percent. Diamond values are expressed as value/carat/hundred tonnes. 

Hematite - An oxide of iron, and one of that metal's most common ore minerals.

High grade - Rich ore. As a verb, it refers to selective mining of the best ore in a deposit.

Host rock - The rock surrounding an ore deposit.

Hydrometallurgy - The treatment of ore by wet processes, such as leaching, resulting in the solution of a metal and its subsequent recovery.

Hydrothermal - Relating to hot fluids circulating in the earth's crust.

Igneous rocks - Rocks formed by the solidification of molten material from far below the earth's surface.

Intermediate rock - An igneous rock containing 52% to 66% quartz.

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

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

Magma - The molten material deep in the Earth from which rocks are formed.

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

Magnetite - Black, magnetic iron ore, an iron oxide.

Metallurgy - The study of extracting metals from their ores.

Metamorphic rocks - Rocks which have undergone a change in texture or composition as the result of heat and/or pressure. (ex. Sandstone becomes quartzite)

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

Mineral - A naturally occurring homogeneous substance having definite physical properties and chemical composition and, if formed under favorable conditions, a definite crystal form.

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

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

Ore Reserves - The calculated tonnage and grade of mineralization which can be extracted profitably; classified as possible, 

probable and proven according to the level of confidence that can be placed in the data.

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

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

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

Pellet - A marble-sized ball of iron ore fused with clay for transportation and use in steelmaking.

Pentlandite - Nickel iron sulphide, the most common nickel ore.

Pig iron - Crude iron from a blast furnace.

Pitchblende - An important uranium ore mineral. It is black in color, possesses a characteristic greasy lustre and is highly radioactive.

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

Primary deposits - Valuable minerals deposited during the original period or periods of mineralization, as opposed to those deposited as a result of alteration or weathering.

Private placement - Sale of shares to individuals or corporations outside the normal market, at a negotiated price. Often used to raise capital for a junior exploration company.

Prospect - A mining property, the value of which has not been determined by exploration.

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

Pulp - Pulverized or ground ore in solution.

Qualified Person - A qualified person (QP) is defined in NI 43-101 as an individual who is an engineer or geoscientist with at least five years of experience in mineral exploration, mine development or operation or mineral project assessment, or any combination of these; has experience relevant to the subject matter of the mineral project and the technical report; and is a member in good standing of a professional association.

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

Quartzite - A metamorphic rock formed by the transformation of a sandstone by heat and pressure.

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

Reconnaissance - A preliminary survey of ground.

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

Reserve - That part of a resource that can be mined at a profit under current or reasonably anticipated economic conditions which are specified. In addition to the information required for a resource estimate, the technical, operating, legal and financial factors must be considered in a reserve estimate.

Reserve (probable) - Part of a resource for which economic viability has been demonstrated at a confidence level which would justify a commitment to major expenditures.

Reserve (proven) - Portion of a resource for which technical and economic factors have been established at a high confidence level. The term is generally restricted to that part of a reserve which is being developed or mined, or for which there is a detailed mining plan.

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

Rock - Any natural combination of minerals; part of the earth's crust.

Run-of-mine - A term used loosely to describe ore of average grade

Sample - A small portion of rock or a mineral deposit taken so that the metal content can be determined by assaying.

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

Scaling - The act of removing loose slabs of rock from the back and walls of an underground opening, usually done with a hand-held scaling bar or with a boom-mounted scaling hammer.

Scintillation counter - An instrument used to detect and measure radioactivity by detecting gamma rays; more sensitive than a geiger counter.

Secondary enrichment - Enrichment of a vein or mineral deposit by minerals that have been taken into solution from one part of the vein or adjacent rocks and redeposited in another.

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

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

Silica - Silicon dioxide. Quartz is a common example.

Siliceous - A rock containing an abundance of quartz.

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

Staking - The measuring of an area of ground and marking with stakes or posts to establish and acquire mineral rights.

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

Sulphide - A compound of sulphur and some other element.

Taconite - A highly abrasive iron ore.

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

Tailings pond - A low-lying depression used to confine tailings from the mine operation, the prime function of which is to allow enough time for heavy metals to settle out or for cyanide to be destroyed before water is either recycled back into the mill operation or treated before discharge into the local watershed.

Talus - A heap of broken, coarse rock found at the base of a cliff or mountain.

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

Uraninite - A uranium mineral with a high uranium oxide content. Frequently found in pegmatite dykes.

Uranium - A radioactive, silvery-white, metallic element.

Vein - A fissure, fault or crack in a rock filled by minerals that have travelled upwards from some deep source.

Volcanic rocks - Igneous rocks formed from magma that has flowed out or has been violently ejected from a volcano.

Wall rocks - Rock units on either side of an orebody. The hangingwall and footwall rocks of an orebody.

Zone - An area of distinct mineralization.

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