Definitions for the language of the gold mining industry


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

Cone crusher

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


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


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

Contact metamorphism

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

Continuous miner

A piece of mining equipment which produces a continuous flow of ore from the working face.

Controlled blasting

Blasting patterns and sequences designed to achieve a particular objective. Cast blasting, where the muck pile is cast in a particular direction, and deck blasting, where holes are loaded once but blasted in successive blasts days apart, are examples.


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

Core barrel

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

Country rock

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


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


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

Cut value

Applies to assays that have been reduced to some arbitrary maximum to prevent erratic high values from inflating the average.


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

Cut-off grade

The lowest grade of material that can be mined and processed considering all applicable costs, without incurring a loss or gaining a profit.


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


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

Debt financing

Method of raising capital whereby companies borrow money from a lending institution.


The area around the shaft collar where men and materials enter the cage to be lowered underground.


A sloping underground opening for machine access from level to level or from surface; also called a ramp.


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