mineral

Fluorite

Calcium Fluoride (CaF2)

Hardness: 4 on Mohs scale; Color: Light green to teal/blue; Luster: Vitreous; Crystal structure: Isometric (cubic); Cleavage: Perfect octahedral; Specific gravity: 3.17-3.56

Hardness: 4 on Mohs scale
Color: Light green to teal/blue
Luster: Vitreous

Identified July 18, 2026More mineral →

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Physical properties

Hardness: 4 on Mohs scale; Color: Light green to teal/blue; Luster: Vitreous; Crystal structure: Isometric (cubic); Cleavage: Perfect octahedral; Specific gravity: 3.17-3.56

Formation & geological history

Formed primarily in hydrothermal veins as a gangue mineral, often associated with metallic ores like lead and silver. It can also occur in granites, pegmatites, and some sedimentary rocks like limestone.

Uses & applications

Used as a flux in steel and aluminum smelting (fluorospar), in the manufacture of hydrofluoric acid, in high-performance optical lenses, and as a popular semi-precious gemstone for jewelry and carvings.

Geological facts

Fluorite gave the name to the phenomenon of fluorescence because many specimens glow under ultraviolet light. It is often called the most colorful mineral in the world.

Field identification & locations

Identified in the field by its distinct vitreous luster, relatively low hardness (can be scratched by a steel knife), and its characteristic four directions of perfect cleavage forming octahedrons. Commonly found in China, Mexico, and the USA (Illinois/Kentucky fluorite district).