Scoria is the waste material that floats to the top of a molten metal bath during extraction. It consists of oxidized impurities, gangue from the ore, and fluxing agents. While often used interchangeably with slag, scoria usually implies a highly vesicular, rough, and cindery texture formed by escaping gases as the waste cools.
Heard on the job
Skim the scoria off the top of the crucible before you attempt the pour.
Also heard as
- dross
- cinder