- a common mineral, calcium fluoride, CaF2, occurring in green, blue, purple, yellow, or colorless crystals, usually in cubes: the principal source of fluorene, used also as a flux in metallurgy and for ornament.
- a white or colourless mineral sometimes fluorescent and often tinted by impurities, found in veins and as deposits from hot gases. It is used in the manufacture of glass, enamel, and jewellery, and is the chief ore of fluorine. Composition: calcium fluoride. Formula: CaF 2 . Crystal structure: cubic
