mineral

Fluorite

Calcium Fluoride (CaF2)

Hardness: 4 on Mohs scale; Color: Light green to blue-green (as shown); Luster: Vitreous/glassy; Crystal structure: Cubic/Isometric; Cleavage: Perfect octahedral; Specific gravity: 3.175–3.184.

Hardness: 4 on Mohs scale
Color: Light green to blue-green (as shown)
Luster: Vitreous/glassy

Identified June 9, 2026More mineral →

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Physical properties

Hardness: 4 on Mohs scale; Color: Light green to blue-green (as shown); Luster: Vitreous/glassy; Crystal structure: Cubic/Isometric; Cleavage: Perfect octahedral; Specific gravity: 3.175–3.184.

Formation & geological history

Formed through hydrothermal activity in veins where hot, mineral-rich fluids circulate through host rocks. It frequently occurs alongside minerals like quartz and calcite in variety of geological ages from Paleozoic to more recent.

Uses & applications

Used as a flux in steel making, in the manufacture of hydrofluoric acid, as high-clarity lenses for telescopes/cameras, and for decorative ornamental carving and gemstone jewelry.

Geological facts

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

Field identification & locations

Identify in the field by its characteristic 4 directions of perfect cleavage and lower hardness (can be scratched by a steel knife but not a copper penny). Often found in limestone cavities and mining districts like those in Illinois or China.