mineral

Fluorite

Calcium Fluoride (CaF2)

Hardness: 4 on Mohs scale; Color: Purple, green, yellow, or multi-colored; Luster: Vitreous (glassy); Crystal Structure: Cubic or octahedral; Cleavage: Perfect octahedral; Specific Gravity: 3.18

Hardness: 4 on Mohs scale
Color: Purple, green, yellow, or multi-colored
Luster: Vitreous (glassy)

Identified June 28, 2026More mineral →

Explore Fluorite in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Hardness: 4 on Mohs scale; Color: Purple, green, yellow, or multi-colored; Luster: Vitreous (glassy); Crystal Structure: Cubic or octahedral; Cleavage: Perfect octahedral; Specific Gravity: 3.18

Formation & geological history

Formed through hydrothermal activity where fluorine-rich fluids pass through limestone or other rocks. It occurs in veins and as a gangue mineral in metallic ore deposits. Geological ages vary, often associated with tectonic events.

Uses & applications

Used as a flux in steel making, in the production of hydrofluoric acid, in high-performance telescope and camera lenses, and widely as a decorative stone and gemstone for jewelry.

Geological facts

Fluorite is where the term 'fluorescence' originated, as many specimens glow under ultraviolet light. It is often called 'the most colorful mineral in the world' due to its wide range of hues.

Field identification & locations

Identify by its relatively low hardness (can be scratched by a knife but not a penny) and its perfect four-way cleavage. Commonly found in China, Mexico, South Africa, and the Illinois-Kentucky fluorspar district.