mineral

Rough Green Fluorite

Fluorite (Calcium Fluoride - CaF2)

Hardness: 4 (Mohs scale); Color: Pale to deep green; Luster: Vitreous (glassy); Crystal Structure: Isometric/Cubic; Cleavage: Perfect octahedral in four directions; Specific Gravity: 3.175–3.184.

Hardness: 4 (Mohs scale)
Color: Pale to deep green
Luster: Vitreous (glassy)

Identified March 13, 2026More mineral →

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Physical properties

Hardness: 4 (Mohs scale); Color: Pale to deep green; Luster: Vitreous (glassy); Crystal Structure: Isometric/Cubic; Cleavage: Perfect octahedral in four directions; Specific Gravity: 3.175–3.184.

Formation & geological history

Fluorite typically forms through hydrothermal processes, occurring as a late-crystallization mineral in felsic igneous rocks or by filling cavities in limestone through hot, mineral-rich fluids. It can be found in deposits ranging from the Precambrian to the Tertiary period.

Uses & applications

Used industrially as a flux for smelting steel and aluminum, in the manufacture of hydrofluoric acid, and for high-clarity lenses in telescopes and cameras. In jewelry and collecting, it is popular for decorative carvings and lapidary work despite its low hardness.

Geological facts

Fluorite is the origin of the term 'fluorescence' 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 trace elements that can change its hue.

Field identification & locations

Identify in the field by its distinct cubic crystal habit (if present) and its relative softness compared to quartz; it can be scratched by a steel knife. Common locations include China, Mexico, South Africa, and the Illinois-Kentucky Fluorspar District in the USA.

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