mineral

Fluorite

Calcium Fluoride (CaF2)

Hardness: 4 (Mohs scale); Color: Purple, green, clear, or multicolored; Luster: Vitreous (glassy); Crystal structure: Isometric/Cubic; Cleavage: Perfect octahedral in four directions; Specific gravity: 3.1

Hardness: 4 (Mohs scale)
Color: Purple, green, clear, or multicolored
Luster: Vitreous (glassy)

Identified July 21, 2026More mineral →

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Physical properties

Formation & geological history

Formed in hydrothermal veins usually associated with lead and zinc ores, or in vugs and cavities in sedimentary rocks like limestone. Often found in deposits dating from the Carboniferous and Permian periods.

Uses & applications

Used as a flux in steel making, in the manufacture of hydrofluoric acid, in high-performance telescope and camera lenses, and widely used as a decorative material for jewelry and mineral collecting.

Geological facts

Fluorite is the source of the word 'fluorescence' because many specimens glow under UV light. It is often referred to as 'the most colorful mineral in the world' due to the huge variety of colors it can exhibit.

Field identification & locations

Identify by its perfect 4-way cleavage (often breaking into double pyramids), its 4.0 hardness which can be scratched by a steel knife but not a copper coin, and its glassy luster. Common locations include Illinois (US), England, China, and Mexico.