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: 3.17 to 3.56.

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

Identified June 23, 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: 3.17 to 3.56.

Formation & geological history

Formed through hydrothermal activity in veins alongside metallic ores or as a late-crystallizing mineral in granites. Often found in limestone and dolostone via replacement processes.

Uses & applications

Used as a flux in steel making, in the manufacture of opalescent glass, and as a source of fluorine for hydrofluoric acid. High-quality specimens are used in carvings and jewelry, though its softness limits use.

Geological facts

Fluorite is often called the most colorful mineral in the world. It is the defining mineral for hardness 4 on the Mohs scale and often exhibits strong fluorescence under UV light.

Field identification & locations

Identify in the field by its glassy luster, octahedral cleavage (forming triangles), and softness (it can be scratched by a pocket knife but not a copper penny). Common locations include Illinois (USA), China, and Mexico.