a soft, heavy, orthorhombic mineral, barium sulfate, BaSO, that is the chief ore of barium, used in making paint, drilling mud, etc.
See barite in American Heritage Dictionary 4
(bârˈīt, bărˈ-) also ba·ry·tes(bə-rīˈtēz)
noun
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.