Fluorite
Image: Arenamontanus (CC BY 2.0)
Mineral NameFluorite
Chemical FormulaCaF2
Mohs Hardness4
Crystal Systemcubic
Lustervitreous
Streak Colorwhite
Cleavageperfect octahedral (four directions)
Fractureconchoidal
Specific Gravity3.18
Colorspurple, colorless, violet
Transparencytransparent
Type LocalityIllinois, USA; Derbyshire, England; Naica, Mexico; Hunan, China
Mineral GroupHalides
Usesflux in steelmaking, hydrofluoric acid production, optical lenses, jewelry, collector
Associated Mineralsquartz, calcite, barite, galena, sphalerite
Raritycommon
Description
The image shows a translucent to transparent fluorite crystal, exhibiting distinct purple and colorless banding, characteristic of its octahedral cleavage. The specimen casts a shadow, highlighting its crystalline form and internal clarity.
Geological Context
Fluorite typically forms in hydrothermal veins, often associated with metallic ores, and also occurs in pegmatites and some sedimentary rocks. It crystallizes from hot aqueous solutions rich in calcium and fluorine.
