mineral

Fluorite

Fluorite (Calcium Fluoride, CaF2)

Hardness: 4 on the Mohs scale. Color: Deep purple/violet (common varieties can be green, blue, yellow, or clear). Luster: Vitreous (glassy). Crystal Structure: Isometric/Cubic. Cleavage: Perfect octahedral cleavage in four directions. Specific Gravity: 3.1

Hardness: 4 on the Mohs scale
Luster: Vitreous (glassy)

Identified March 29, 2026More mineral →

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Physical properties

Formation & geological history

Formed primarily in hydrothermal veins often associated with lead and zinc minerals. It can also form in sedimentary environments like limestone or in igneous granitic rocks. It occurs across various geological ages from the Precambrian to more recent eras depending on the specific deposit.

Uses & applications

Used as a flux in steel making (metallurgical grade), in the manufacture of hydrofluoric acid (acid grade), high-quality camera lenses and telescopes (optical grade), and widely used in jewelry (cabochons) and as decorative mineral specimens for collectors.

Geological facts

Fluorite gave its name to the phenomenon of fluorescence because many specimens glow under ultraviolet light. It is often called 'the most colorful mineral in the world'. The term 'fluorspar' is frequently used in industrial contexts.

Field identification & locations

Field identification is based on the distinct cubic crystal habit, the inability to be scratched by a knife but easily scratched by a penny, and its perfect cleavage. Common locations include the Illinois-Kentucky fluorspar district (USA), China, Mexico, and Derbyshire (UK). Collectors should look for well-defined cubes and deep saturation.