- a white, crystalline, water-insoluble, tasteless powder, CaCO3, occurring in nature in various forms, as calcite, chalk, and limestone: used chiefly in dentifrices and polishes and in the manufacture of lime and cement.
- a white crystalline salt occurring in limestone, chalk, marble, calcite, coral, and pearl: used in the production of lime and cement. Formula: CaCO 3
