Mining Glossary

Mining Glossary

To help you through some of the inevitable mining and finance jargon we have produced the following glossary.

Adit - an almost horizontal entrance to a mine.

Alloy  a compound of two or more metals.

Alluvium deposit of sedimentary material laid down in river beds, lakes, flood plains or at the base of mountain slopes.

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 under mining law that must be performed each year in order to retain legal control of mining claims.

Backfill waste material used to fill the void created by mining.

Back sample rock samples collected from an excavated area for the purpose of determining grade.

Base metal this is, strictly, the oxide form of any metal but is commonly referred to as being the non-precious metals that are traded on the London Metal Exchange.

Call factor the fraction of an ore reserve that is successfully mined.

Carat the unit of weight for gemstones (one carat weighs 200 mg).

Carlin type deposit very fine grain gold. The Carlin Trend is situated in northeastern Nevada and consists of a 60km northwest/southeast line of major gold deposits.

CIL - carbon-in-leach process which integrates leaching and carbon-in-pulp into a single unit process operation.

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

Contango - a condition in which distant delivery prices exceed spot prices, often due to the costs of storing and insuring the underlying commodity. The opposite situation is called backwardation.

Cut-off grade The grade below which mineralisation is not included in the assessment of ore resources/reserves.

Cyanidation a method using a weak cyanide solution by which gold or silver grains are extracted from ore.

Deposit a body of rock containing a concentration of minerals.

Development drilling drilling to establish accurate estimates of mineral reserves.

Dilution the necessary mining of waste rock, along with ore. Measured as the ratio of waste rock to the total amount of rock mined.

Drift a horizontal underground development that follows along the length of a rock formation as opposed to a crosscut, which crosses the rock formation.

Enechelon - a geologic feature that follows a zigzag fault pattern.

EPC - engineering, procurement and construction.

EPCM - engineering, procurement and construction management.

Feasibility study an economic study assessing whether a mineral deposit can be mined profitably.

Gabbro a dark, basic, coarse-grained igneous rock.

Garimpeiro - clandestine prospector or miner.

Garimpo - mine, claim or prospect.

Gross value the theoretical value of ore determined by applying the assessed grade of metal(s) in the ore by the relevant current market price.

High grade rich ore.

Induced polarisation - a geophysical method and developed for ore exploration.

JORC code widely accepted standard for reporting mineral resources and ore reserves established by the Australasian Joint Ore Reserves Committee.

Kimberlite pipe an orebody shaped like a flute or pipe which can contain diamonds.

Laterite ore ore occurring in the form of soil residue containing secondary oxides of metal, often associated with nickel.

Leaching a chemical process for the extraction of valuable minerals from ore.

Lode a mineral deposit in solid rock.

Longwall a mining method (common on South African gold mines and European coal mines) involving straight, and narrow, working faces.

Measured resource a resource whose size and grade have been estimated from sampling at intervals that are spaced closely enough together so that the deposit's continuity is essentially confirmed.

National Instrument 43-101 - Canadian rule that governs how issuers disclose scientific and technical information about their mineral projects to the public.

Noble metal a metal or alloy, such as gold, that is highly resistant to oxidation and corrosion.

Nomad A firm or company which has been approved by the London Stock Exchange as a nominated adviser for the Alternative Investment Market (AIM).

Open pit a mine that is entirely on the surface. Also referred to as open-cut or an open-cast mine (the latter normally for coal and industrial mineral operations).

Option an agreement in which the buyer has the right to exercise by buying or selling an asset at a set price on or before a future date. The seller has an obligation to honour the terms of the contract.

Paste-fill back-filling of mined-out underground areas with finely ground rock in a slurry.

PPM parts per million, also gram/tonne

PPB - parts per billion.

Primary deposits valuable minerals deposited during the original period of mineralisation, as opposed to those deposited as a result of alteration or weathering.

Probable reserves valuable mineralisation that is not yet sampled sufficiently to be proven.

Put option - an option which gives the holder the right but not the obligation to sell shares (or other financial instruments) at a fixed price on or before a given date.

Reserve the part of a mineral resource that can be mined profitably.

SAG mill semi-autogenous grinding mill.

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

Stope an excavation in a mine from which ore is extracted (usually in a longwall).

Strike length the distance and direction along which drilling results have established mineralisation.

SX/EW - solvent extraction, electrowinning.

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

Trend the direction, in the horizontal plane, of a linear geological feature, such as an ore zone.

UTEM deep electromagnetic survey.

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

Warrant - a derivative security that gives the holder the right to purchase securities (usually equity) from the issuer at a specific price within a certain time frame. Warrants are often included in a new debt issue as a sweetener to entice investors.