mineral

Fluorite

Calcium Fluoride (CaF2)

Hardness: 4 on Mohs scale. Color: Green, purple, and clear banding. Luster: Vitreous (glassy). Crystal Structure: Isometric/Cubic. Cleavage: Perfect octahedral. Specific Gravity: 3.175–3.184.

Hardness: 4 on Mohs scale
Color: Green, purple, and clear banding
Luster: Vitreous (glassy)

Identified July 2, 2026More mineral →

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Physical properties

Hardness: 4 on Mohs scale. Color: Green, purple, and clear banding. Luster: Vitreous (glassy). Crystal Structure: Isometric/Cubic. Cleavage: Perfect octahedral. Specific Gravity: 3.175–3.184.

Formation & geological history

Forms through hydrothermal activity, often filling veins in metallic ores or in sedimentary rocks like limestone. It precipitates as hot, mineral-rich fluids cool within earth cavities.

Uses & applications

Used in metallurgy as a flux to lower smelting temperatures, in the production of hydrofluoric acid, in high-performance telescope lenses, and as a popular ornamental gemstone.

Geological facts

Fluorite is the most colorful mineral in the world. It is the defining mineral for hardness 4 on the Mohs scale and is the namesake for the phenomenon of fluorescence because many specimens glow under UV light.

Field identification & locations

Identified in the field by its distinct four directions of perfect cleavage and its relatively low hardness (can be scratched by a steel blade, unlike quartz). Common locations include China, Mexico, South Africa, and the Illinois-Kentucky fluorspar district in the USA.