Gangue

Gangue is the worthless substance that is left behind when minerals are processed.

When minerals are collected, the ore that is wanted is found only in small amounts. Flotation is used to concentrate the ore. The ore floats while the gangue sinks to the bottom. Sometimes minerals thought of as gangue are later recovered and used.

Gangue Media

Crystals of cassiterite, a commercially valuable ore mineral, in a matrix of quartz, the gangue
Banded Zn-Pb ore sample with sphalerite (brown) and galena as main ore minerals and calcite as main gangue mineral (old Bad Grund mine, Germany)

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