mineral

Fluorite

Calcium Fluoride (CaF2)

Hardness: 4 on Mohs scale; Color: Purple, green, clear, and white banding; Luster: Vitreous (glassy); Crystal structure: Cubic/Isometric; Cleavage: Perfect octahedral; Specific Gravity: 3.18

Hardness: 4 on Mohs scale
Color: Purple, green, clear, and white banding
Luster: Vitreous (glassy)

Identified July 15, 2026More mineral →

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Physical properties

Hardness: 4 on Mohs scale; Color: Purple, green, clear, and white banding; Luster: Vitreous (glassy); Crystal structure: Cubic/Isometric; Cleavage: Perfect octahedral; Specific Gravity: 3.18

Formation & geological history

Formed through hydrothermal activity, often found in veins where hot, mineral-rich water flows through fractures in limestone or other rocks. Can be found in sedimentary environments and as an accessory mineral in igneous rocks.

Uses & applications

Used as a flux in steelmaking and aluminum production, in the manufacture of hydrofluoric acid, specialized optical lenses for telescopes/cameras, and extensively as a semi-precious gemstone for jewelry and ornamental carving.

Geological facts

Fluorite is the original source of the term 'fluorescence' because many specimens glow under UV light. It is often called 'the most colorful mineral in the world' due to its wide range of vibrant colors caused by various elemental impurities.

Field identification & locations

Identify by its characteristic purple/green banding, relatively low hardness (can be scratched by a pocket knife but not a copper penny), and its perfect octahedral cleavage which often results in triangular or diamond-shaped faces on broken pieces. Common in China, Mexico, and Illinois (USA).