mineral

Fluorite

Calcium Fluoride (CaF2)

Hardness of 4 on the Mohs scale, various colors including purple, green, blue, and yellow, vitreous luster, isometric crystal system with octahedral cleavage, specific gravity of 3.18.

Identified July 30, 2026More mineral →

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Physical properties

Hardness of 4 on the Mohs scale, various colors including purple, green, blue, and yellow, vitreous luster, isometric crystal system with octahedral cleavage, specific gravity of 3.18.

Formation & geological history

Formed in hydrothermal veins, often associated with metallic ores like lead and zinc, as well as in carbonate rocks like limestone and dolostone.

Uses & applications

Used in the manufacture of hydrofluoric acid, as a flux in steelmaking, in optics for lenses, and as a popular mineral specimen for collectors.

Geological facts

Fluorite is the defining mineral for a hardness of 4 on the Mohs scale and exhibits strong fluorescence under ultraviolet light, a phenomenon named after the mineral itself.

Field identification & locations

Easily identified by its relatively low hardness (can be scratched with a knife), perfect octahedral cleavage, and often beautiful zoning of colors. Commonly found in China, Mexico, South Africa, and the UK.