mineral

Fluorite

Calcium Fluoride (CaF2)

Hardness: 4 on Mohs scale; Color: typically green, purple, blue, or yellow; Luster: Vitreous (glass-like); Crystal structure: Isometric (cubic/octahedral); Cleavage: Perfect octahedral; Specific gravity: 3.18

Hardness: 4 on Mohs scale
Color: typically green, purple, blue, or yellow
Luster: Vitreous (glass-like)

Identified March 22, 2026More mineral →

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Physical properties

Formation & geological history

Formed in hydrothermal veins usually associated with metallic ores. Often occurs as a gangue mineral in lead, silver, and zinc deposits across various geological ages from Precambrian to Cenozoic.

Uses & applications

Used as a flux for smelting steel/aluminum (fluorspar), in the manufacture of high-clarity lenses for cameras/telescopes, as a source of hydrofluoric acid, and widely as a semi-precious gemstone/ornamental stone.

Geological facts

Fluorite is famously fluorescent under UV light; the phenomenon of 'fluorescence' was actually named after this mineral. It is often called 'the most colorful mineral in the world.'

Field identification & locations

Identify in the field by its 4th-degree hardness (can be scratched by a pocket knife but not a copper coin) and its perfect cleavage, which often results in clean triangle-shaped facets on broken surfaces. Found worldwide with major deposits in China, Mexico, and Illinois, USA.