mineral

Fluorite

Calcium Fluoride (CaF2)

Hardness: 4 on Mohs scale; Color: Blue, purple, green, translucent; Luster: Vitreous (glass-like); Crystal structure: Isometric/cubic; Cleavage: Perfect octahedral in 4 directions; Specific gravity: 3.18

Hardness: 4 on Mohs scale
Color: Blue, purple, green, translucent
Luster: Vitreous (glass-like)

Identified July 24, 2026More mineral →

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Physical properties

Formation & geological history

Forms primarily through hydrothermal processes in veins, often associated with metallic ores like lead, zinc, and silver, as well as in limestones and granite pegmatites.

Uses & applications

Used widely as a flux in steelmaking, in the production of hydrofluoric acid, as lapidary material for carvings and beads, and highly valued by mineral collectors.

Geological facts

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

Field identification & locations

Can be identified by its relatively low hardness (easily scratched by a steel nail), perfect octahedral cleavage, vitreous luster, and distinct purple to blue color bands. Common in China, Mexico, South Africa, and the USA.