mineral

Fluorite

Calcium Fluoride (CaF2)

Hardness: 4 on Mohs scale. Color: Range of purple, green, yellow, and clear (this specimen appears purplish-tan). Luster: Vitreous (glassy). Crystal Structure: Isometric/Cubic. Cleavage: Perfect octahedral in four directions. Specific Gravity: 3.18.

Hardness: 4 on Mohs scale
Luster: Vitreous (glassy)

Identified July 7, 2026More mineral →

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Physical properties

Formation & geological history

Forms as a late-stage mineral in hydrothermal veins, often associated with metallic ores like lead and silver. It can also form in sedimentary rocks like limestone or through sublimation in volcanic environments.

Uses & applications

Used as a flux in steel making, in the manufacture of hydrofluoric acid, in high-performance telescope and camera lenses, and widely as a semi-precious gemstone and for ornamental carvings.

Geological facts

Fluorite is the origin of the term 'fluorescence' because many specimens glow under ultraviolet light. It is often referred to as 'the most colorful mineral in the world'.

Field identification & locations

Identified in the field by its relatively low hardness (can be scratched by a knife but not a copper penny) and its distinctive octahedral cleavage. Commonly found in China, Mexico, South Africa, and the Illinois-Kentucky fluorspar district in the USA.