Natural Fluorite — Rough

Fluorite is a calcium halide with the chemical formula CaF₂, being the most representative mineral of the group of fluorides. It forms predominantly in low to medium temperature hydrothermal veins, associated with minerals such as quartz, calcite, barite and metallic sulfides, in addition to occurring in pegmatites and as a contact mineral in carbonate rocks. Its color is extremely variable — colorless, green, purple, blue, yellow, pink and black — determined by the presence of impurities, ionic substitutions and defects in the crystalline network generated by exposure to natural radiation. The green results from traces of ytterbium and other rare earth elements; the purple and blue derive from structural defects associated with irradiation and the presence of europium. It presents perfect octahedral cleavage in four directions and characteristic fluorescence under ultraviolet light, a phenomenon that takes its name from the mineral itself. Hardness: 4 on the Mohs scale. Density: 3.17 to 3.56 g/cm³. Crystalline system: cubic. Available variations, approximate data: 1 to 3 cm — Approx. 0.010 kg — 250 pcs per kg 3 to 6 cm — 0.030 to 0.150 kg — 30 pieces per kg 6 to 15 cm — 0.150 to 0.800 kg — 2 to 3 pieces per kg