The part of an ore deposit that is too low grade to be of economic value at the time of mining, but which may be stored separately for possible treatment later.

ore rock mined with an insufficient gold content to justify processing.

Rock lacking sufficient grade and/or other characteristics of ore to be commercially exploited.[X, Y, Z

Rock lacking suffiencient grade and/or other characterisitcs of ore to be economical.

Barren rock or mineralized material that is too low in grade to be economically processed.

Rock containing no ore but removed in the course of mining operations.

Unmineralized rock, or sometimes mineralized rock that is not minable at a profit.

Barren rock in a mine, or mineralized material that is too low in grade to be mined and milled at a profit.

That rock or mineral which must be removed from a mine to keep the mining scheme practical, but which has no value.