mineral

Fluorite

Calcium Fluoride (CaF2)

Hardness: 4 on Mohs scale; Color: typically green, purple, yellow, or blue; Luster: vitreous (glassy); Crystal structure: isometric/cubic; Cleavage: perfect octahedral; Specific gravity: 3.18

Hardness: 4 on Mohs scale
Color: typically green, purple, yellow, or blue
Luster: vitreous (glassy)

Identified March 15, 2026More mineral →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Hardness: 4 on Mohs scale; Color: typically green, purple, yellow, or blue; Luster: vitreous (glassy); Crystal structure: isometric/cubic; Cleavage: perfect octahedral; Specific gravity: 3.18

Formation & geological history

Usually forms in hydrothermal veins, often associated with metallic ores. It can be found in sedimentary environments or as an accessary mineral in igneous rocks like granites.

Uses & applications

Used in the manufacture of steel, glass, and hydrofluoric acid. High-clarity specimens are used for specialized optical lenses. Tumbled stones are used in jewelry and crystal collecting.

Geological facts

Fluorite is the origin of the term 'fluorescence' because many specimens glow under ultraviolet light. It is often called 'the most colorful mineral in the world'.

Field identification & locations

Identify in the field by its distinct cubic crystal habit, perfect cleavage into octahedrons, and the fact that it can be scratched by a steel knife but not a copper penny. Common locations include China, Mexico, and Illinois, USA.