Fluorite Tumblestone

Fluorite, also known as fluorspar, is the mineral form of calcium fluoride, which has the chemical formula CaF2. It belongs to the halide group of minerals. Flourite crystallizes in an isometric cubic habit, although octahedral and more complex isometric forms are also found. On the Mohr scale of mineral hardness, flourite has a value of 4.0 Pure fluorite is colourless and transparent, both in visible and ultraviolet light, but impurities usually make it a colorful mineral and the stone is popular for ornamental and lapidary decoration. In industry, fluorite is used as a flux for smelting, and in the production of certain glasses and enamels. The purest grades of fluorite are a source of fluoride for synthesising hydrofluoric acid. Optically clear transparent fluorite lenses have low dispersion, so lenses made from it exhibit less chromatic aberration, making them valuable in microscopes and telescopes. Fluorite optics are also usable in the far-ultraviolet and mid-infrared ranges, where conventional glasses are too opaque for use. Sold in single pieces, sizes may vary