Mineral

Fluorite (Purple Octahedron)

Calcium Fluoride (CaF2)

Hardness: 4 on Mohs scale; Color: Deep purple/violet; Luster: Vitreous (glassy); Crystal Structure: Isometric/Cubic; Cleavage: Perfect octahedral (four directions); Specific Gravity: 3.1

Hardness: 4 on Mohs scale
Color: Deep purple/violet
Luster: Vitreous (glassy)

Identified March 16, 2026More mineral →

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Physical properties

Hardness: 4 on Mohs scale; Color: Deep purple/violet; Luster: Vitreous (glassy); Crystal Structure: Isometric/Cubic; Cleavage: Perfect octahedral (four directions); Specific Gravity: 3.1

Formation & geological history

Formed through hydrothermal activity where hot, mineral-rich fluids circulate through fractures in limestone or igneous rocks. It occurs across various geological ages, often in veins with metallic ores.

Uses & applications

Used as a flux in steel making, in the production of hydrofluoric acid for aluminum smelting, and in glass/enamel industries. High-quality purple specimens are popular for jewelry, lapidary carvings, and mineral collecting.

Geological facts

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

Field identification & locations

Identified in the field by its distinct octahedral shape (often formed by cleaving a cubic crystal), its softness (can be scratched by a steel knife but not a copper penny), and its purple color. Common locations include Illinois (US), China, Mexico, and England.

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