mineral

Fluorite

Calcium fluoride (CaF2)

Hardness: 4 on Mohs scale; Color: Light green to aqua blue; Luster: Vitreous (glassy); Crystal structure: Isometric (often cubic or octahedral); Cleavage: Perfect octahedral; Specific gravity: 3.175–3.184

Hardness: 4 on Mohs scale
Color: Light green to aqua blue
Luster: Vitreous (glassy)

Identified May 30, 2026More mineral →

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Physical properties

Formation & geological history

Fluorite typically forms in hydrothermal veins, often occurring alongside metallic ores like lead and silver. It can also be found in the cavities of sedimentary rocks like limestone. It is found in geological formations ranging from the Precambrian to recent eras.

Uses & applications

Used as a flux in steel and aluminum smelting, in the manufacture of hydrofluoric acid, and for high-performance telescope and camera lenses. High-quality specimens are popular for jewelry (cabochons) and mineral collecting.

Geological facts

The term 'fluorescence' is derived from fluorite because many specimens glow under ultraviolet light. It is often referred to as 'the most colorful mineral in the world' due to the wide variety of colors it can exhibit.

Field identification & locations

Identify in the field by its hardness (can be scratched by a knife but not a copper penny) and its perfect four-directional cleavage. Look for it in mineral-rich vein deposits or as a secondary mineral in limestone and dolomite.