Definitions for the language of the gold mining industry


A chemical compound consisting of the element tellurium and another element, often gold or silver.


A large, round tank used in milling operations to separate solids from liquids; clear fluid overflows from the tank and rock particles sink to the bottom.


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


One tonne is equal to 1,000 kilograms (also known as a “metric” ton).


Common unit used to describe the amount of ore in a deposit; ore length is multiplied by the width and divided by the appropriate rock factor to give the amount of ore for each vertical metre of depth.

Total cash costs

Total cash costs, as defined in the Gold Institute’s guidance, include mine production, transport and refinery costs, general and administrative costs, movement in production inventories and ore stockpiles, and royalties.  Total cash costs exclude costs associated with capitalised stripping activities.


is a crystal boron silicate mineral.


To haul ore or waste in a mine.


A long, narrow excavation dug through overburden, or blasted out of rock, to expose a vein or ore structure.


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


Rock composed of fine volcanic ash.


A horizontal underground opening, open to the atmosphere at both ends.


A machine used to excavate a tunnel through soil or rock by mechanical means as opposed to drilling and blasting.


An igneous rock with a very low silica content and rich in iron magnesium minerals.

Umpire sample or assay

An assay made by a third party to provide a basis for settling disputes between buyers and sellers of ore.

Uncut value

The actual assay value of a core sample as opposed to a cut value which has been reduced by some arbitrary formula.


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

Visible gold (VG)

Native gold which is discernible, in a hand specimen, to the unaided eye.

Volcanic rocks

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


Where volcanic derived material has been transported and reworked through mechanical processes.


© Copyright 2015 - Randgold Resources Limited