fluorite or fluorspar, mineral appearing in various colors, e.g., green, yellow-brown, rose, and red. Chemically, it is calcium fluoride, CaF₂. Its crystals, commonly cubic, are transparent or translucent and under certain conditions exhibit fluorescence. The mineral also occurs in granular and massive forms. Fluorite is found in various parts of the world, especially in England, Germany, Mexico, and in Kentucky and Illinois in the United States. Its chief use is as a flux in metallurgy, but it is also employed in the preparation of hydrofluoric acid and in the manufacture of opal glass and enamel; some of its colorless crystals are used for making lenses and prisms.

or fluorspar

Common halide mineral, calcium fluoride (CaF₂); the principal fluorine mineral. Fluorite occurs most commonly as a vein mineral and is often associated with lead and silver ores; it also occurs in cavities, sedimentary rocks, pegmatites, and hot-springs areas. It is widespread in China, South Africa, Mongolia, France, Mexico, Russia, and the central U.S. Fluorite is used in the manufacture of steel, aluminum fluoride, artificial cryolite, and aluminum. It is used in glassmaking, in iron and steel enamelware, in the production of hydrofluoric acid, in the refining of lead and antimony, and (as a catalyst) in the manufacture of high-octane fuels.

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