mineral

Fluorite

Calcium Fluoride (CaF2)

Hardness: 4 on Mohs scale; Color: Green, yellow, purple, or colorless; Luster: Vitreous (glassy); Crystal Structure: Isometric/Cubic; Cleavage: Perfect octahedral in four directions; Specific Gravity: 3.18

Hardness: 4 on Mohs scale
Color: Green, yellow, purple, or colorless
Luster: Vitreous (glassy)

Identified April 5, 2026More mineral →

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Physical properties

Formation & geological history

Formed as a hydrothermal mineral in veins, typically appearing in metallic ore deposits. It can occur in sedimentary rocks as a cementing material or in igneous rocks as an accessory mineral. Its formation spans across various geological ages from Precambrian to recent deposits.

Uses & applications

Used as a flux in steel and aluminum smelting; manufacturing of hydrofluoric acid; high-grade lenses for microscopes and telescopes; gemstone use in jewelry (though soft); and as a popular collector's specimen.

Geological facts

Fluorite is the origin of the term 'fluorescence' because many specimens glow under ultraviolet light. It is often called 'the most colorful mineral in the world' due to its wide range of vibrant hues caused by impurities.

Field identification & locations

Identify by its characteristic 4-way octahedral cleavage, glass-like luster, and its ability to be scratched by a knife but not a copper penny. Commonly found in locations like China, Mexico, South Africa, and the Illinois-Kentucky fluorspar district in the USA.