mineral

Fluorite

Calcium Fluoride (CaF2)

Hardness: 4 on Mohs scale; Color: Pale green to bluish-green; Luster: Vitreous (glassy); Crystal Structure: Isometric (cubic); Cleavage: Perfect octahedral in four directions; Specific Gravity: 3.17 to 3.56.

Hardness: 4 on Mohs scale
Color: Pale green to bluish-green
Luster: Vitreous (glassy)

Identified July 21, 2026More mineral →

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Physical properties

Formation & geological history

Commonly forms in hydrothermal veins where it occurs as a gangue mineral associated with metallic ores. It can also form in sedimentary rocks such as limestones and dolomites in areas of volcanic activity.

Uses & applications

Used as a flux in steel making, in the manufacture of hydrofluoric acid, in high-performance telescopes and camera lenses (as fluorite glass), and as a popular ornamental and collector mineral.

Geological facts

Fluorite was the first mineral from which the phenomenon of fluorescence was studied and named. It is sometimes called 'the most colorful mineral in the world' due to the huge range of colors it can exhibit.

Field identification & locations

Identify by its softness (can be scratched by a knife but not a penny), its perfect octahedral cleavage, and its often translucent to transparent glassy appearance. Found worldwide including significant deposits in China, Mexico, England, and the United States (Illinois and Kentucky).