fluorite

views updated May 08 2018

fluorite (fluorspar, Blue John) Mineral, CaF2;sp. gr. 3.2; hardness 4; cubic; often yellow, green, blue, or purple, but can be colourless, pink, red, or black, and often colour banded; white streak; vitreous lustre; crystals often cubes, but can be octahedra and rhombdodecahedra, and a mixture of forms; cleavage perfect {111}; widely distributed in mineral veins alone or as a gangue mineral with metallic ores, and in association with quartz, barite, calcite, galena, cassiterite, sphalerite, and many other minerals; soluble in sulphuric acid with the evolution of hydrogen sulphide. It is used extensively as a flux in the smelting of iron, in the ceramic industry, and in the chemical industry. The deep-purple, banded variety, Blue John, is used as an ornamental stone.

fluorite

views updated Jun 08 2018

fluo·rite / ˈfloŏrˌīt; flôr-/ • n. a mineral consisting of calcium fluoride that typically occurs as cubic crystals, colorless when pure but often colored by impurities.

fluorite

views updated May 23 2018

fluorite (fluorspar) Mineral, calcium fluoride (CaF2). It has cubic system crystals with granular and fibrous masses. Brittle and glassy, it can be yellow, purple or green. It is used as a flux in steel production and in ceramics and chemical industries. Hardness 4; r.d. 3.1.