Bau-Mix Ltd.

What is Fluorite?

Fluorite (also called fluorspar) is a mineral composed of calcium fluoride, CaF2. It is an isometric mineral with a cubic habit, though octahedral and more complex isometric forms are not uncommon. Cubic crystals up to 20 cm across have been found at Dalnegorsk, Russia. Crystal twinning is common and adds complexity to the observed crystal habits.

The word fluorite is derived from the Latin root fluo, meaning "to flow" because the mineral has a relatively low melting point and was used as an important flux in smelting. Fluorite gave its name to its constitutive element fluorine.

Fluorite primarily occurs as a pore-filling mineral in carbonate rocks (limestones and dolostones), as low temperature hydrothermal vein deposits associated with lead and silver ores, and less often as an accessory mineral in pegmatites and granites. It is sometimes even precipitated at hot springs.

Limestone and dolostone rocks through which low temperature hydrothermal fluids have moved may be particularly rich in fluorite. When fluorite occurs as a cavity fill in carbonate rocks it is usually associated with calcite, dolomite, anhydrite, gypsum and sulfur. In hydrothermal vein deposits, fluorite may be found with calcite, dolomite, barite, galena, sphalerite, and even silver ores.

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.