Definitions for the language of the gold mining industry


A mineral salt typically found in quartz veins and as a product of hydrothermal alteration of sedimentary rock.


A rectangular plate of metal, produced by electrolytic refining, which is melted into commercial shapes such as wirebars, billets, ingots, etc.

Cemented Aggregate Fill

a backfill method for filling open stopes that uses cement and rock aggregate.


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


A copper iron sulfide mineral.

Change house

The mine building where workers change into work clothes; also known as the "dry".

Channel sample

A sample composed of pieces of vein or mineral deposit that have been cut out of a small trench or channel, usually about 10 cm wide and 2 cm deep.

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.


An opening equipped with a gate, through which ore is drawn from a stope.


A vermilion-colored ore mineral of mercury.

Circulating load

Over-sized chunks of ore returned to the head of a closed grinding circuit before going on to the next stage of treatment.


Process of clearing dirty water by removing suspended material.


A mineral-processing machine which separates minerals according to size and density.


Rocks built up of fragments of pre-existing rocks which have been produced by the processes of weathering and erosion.


A fine-grained material composed of hydrous aluminum silicates.


The tendency of a mineral to split along crystallographic planes.

Closed circuit

A loop in the milling process wherein a selected portion of the product of a machine is returned to the head of the machine for finishing to required specification.


The term applied to the timbering or concrete around the mouth of a shaft; also used to describe the top of a mill hole.

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.


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


© Copyright 2015 - Randgold Resources Limited