Fluorite

Physical Properties

Hardness: 4 on Mohs scale. Color: Pale green and purple zoning. Luster: Vitreous (glassy). Crystal Structure: Isometric/Cubic. Cleavage: Perfect octahedral in four directions. Specific Gravity: 3.18.

Formation & Geological History

Formed through hydrothermal activity in veins alongside lead, silver, and zinc ores. Can also occur in sedimentary carbonate rocks and occasionally in igneous pegmatites.

Uses & Applications

Used as a flux in steel making, in the production of hydrofluoric acid, in the manufacturing of high-clarity optical lenses, and as a popular semi-precious gemstone for decorative carvings and jewelry.

Geological Facts

Fluorite is the source of the term 'fluorescence' because many specimens glow under ultraviolet light. It is often called 'The Most Colorful Mineral in the World' due to its wide range of hues.

Field Identification & Locations

Identify by its 'four directions of cleavage' and its hardness; it can be scratched by a steel knife but will scratch a copper penny. Commonly found in Illinois (USA), China, South Africa, and Mexico.

Identified on: 4/23/2026

Mode: Standard