1. A bed or bank of waste material dividing mineral veins or beds.

2. A soft, thin sedimentary layer following a surface of separation between thicker strata of different lithology.

3. A surface along which a hard rock can be readily separated or is naturally divided into layers.

1. Recovery of gold (or occasionally another metal) from its alloys by a corrosion process.

2. Zone of separation between cope and drag portions of mold or flask in sand casting.

3. In sand molding, a composition to facilitate removal of the pattern.

4. A shearing operation to produce two or more parts from a stamping.

Fracturing a mineral along planes weakened by deformation or twinning.