mineral

Fluorite

Calcium Fluoride (CaF2)

Hardness of 4 on the Mohs scale, colors vary widely (green, purple, blue, yellow, clear), vitreous luster, isometric crystal system, perfect octahedral cleavage, specific gravity of 3.18.

Identified July 31, 2026More mineral →

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Physical properties

Hardness of 4 on the Mohs scale, colors vary widely (green, purple, blue, yellow, clear), vitreous luster, isometric crystal system, perfect octahedral cleavage, specific gravity of 3.18.

Formation & geological history

Formed in hydrothermal veins, often associated with metallic ores like lead and zinc, as well as in cavities in sedimentary rocks.

Uses & applications

Used in metallurgy as a flux, in the manufacture of optical equipment (lenses), and heavily collected as mineral specimens and carved into decorative objects.

Geological facts

Fluorite is the mineral reference for a hardness of 4 on the Mohs scale. It exhibits strong fluorescence under ultraviolet light, a phenomenon named after the mineral itself.

Field identification & locations

Easily identified by its relatively low hardness (can be scratched with a knife but not a fingernail), perfect cleavage, and often vibrant cubic or octahedral crystal forms. Found worldwide with notable deposits in China, Mexico, South Africa, and the UK.