mineral

Fluorite

Calcium Fluoride (CaF2)

Hardness: 4 on Mohs scale; Color: typically purple, green, yellow, or colorless in this specimen; Luster: vitreous (glassy); Crystal structure: Isometric (cubic); Cleavage: Perfect octahedral; Specific gravity: 3.175 to 3.56.

Hardness: 4 on Mohs scale
Luster: vitreous (glassy)

Identified July 20, 2026More mineral →

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Physical properties

Formation & geological history

Formed through hydrothermal activity, often in veins or as a gangue mineral in metallic ore deposits. It can also occur in sedimentary rocks like limestone and in some igneous environments such as pegmatites.

Uses & applications

Used as a flux in steel making, in the production of hydrofluoric acid, in high-performance telescopes and camera lenses, and widely collected as ornamental minerals or carved into jewelry and decorative items.

Geological facts

Fluorite is where the term 'fluorescence' comes from, as many specimens glow under ultraviolet light. It is often called 'the most colorful mineral in the world' because it occurs in every color of the rainbow.

Field identification & locations

Identify by its cubic crystal form and perfect cleavage that creates diamond-shaped fragments. It can be scratched by a steel knife but not by a copper penny. Found in famous localities like Illinois (USA), China, Mexico, and England.