Native sulphate of barium, a mineral occurring in transparent, colorless, white to yellow crystals (generally tabular), also in granular form, and in compact massive forms resembling marble. It has a high specific gravity, and hence is often called heavy spar. It is a common mineral in metallic veins.
- A yellow, white, or colorless crystalline mineral of barium sulfate, BaSO4, that is used in paint and as the chief source of barium chemicals. Also called heavy spar.