mineral

Fluorite Octahedron

Fluorite (Calcium Fluoride, CaF2)

Hardness: 4 (Mohs scale); Color: Light green; Luster: Vitreous; Crystal Structure: Isometric; Cleavage: Perfect octahedral; Specific Gravity: 3.175–3.184

Hardness: 4 (Mohs scale)
Color: Light green
Luster: Vitreous

Identified June 12, 2026More mineral →

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Physical properties

Hardness: 4 (Mohs scale); Color: Light green; Luster: Vitreous; Crystal Structure: Isometric; Cleavage: Perfect octahedral; Specific Gravity: 3.175–3.184

Formation & geological history

Forms through hydrothermal activity in veins where hot magma-heated water containing fluorine rises through cracks in limestone; often found with lead and silver ores. Formed across various geological ages.

Uses & applications

Used as a flux in steel making, in the manufacture of hydrofluoric acid, and high-clarity lenses for telescopes and cameras; the octahedral shape is popular for metaphysical use and specimen collecting.

Geological facts

The phenomenon of fluorescence was named after fluorite because many specimens glow under ultraviolet light. The octahedral shape of this specimen is often produced by hand-cleaving natural cubic fluorite crystals along their perfect cleavage planes.

Field identification & locations

Identified in the field by its 4-way cleavage, hardness (can be scratched by a knife but not a penny), and its tendency to form cubes or octahedrons. Commonly found in locations like Illinois (USA), China, and England.

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