Fluorite

Physical Properties

Hardness: 4 on Mohs scale; Color: Green (in this specimen), can be purple, blue, or yellow; Luster: Vitreous; Crystal Structure: Isometric (cubic); Cleavage: Perfect octahedral; Specific Gravity: 3.18

Formation & Geological History

Formed primarily in hydrothermal veins, often associated with metallic ores. It can also occur in various igneous and some sedimentary environments. It forms through precipitation from late-stage magmatic fluids.

Uses & Applications

Used as a flux in steel making, in the production of hydrofluoric acid, in high-performance telescope and camera lenses, and widely as a decorative stone and gemstone.

Geological Facts

Many specimens of fluorite fluoresce under ultraviolet light, a phenomenon named after the mineral itself. It is known as 'the most colorful mineral in the world'.

Field Identification & Locations

Identified by its distinctive 4 on the Mohs scale (softer than glass) and its perfect octahedral cleavage. Found commonly in China, Mexico, South Africa, and the USA (Illinois/Kentucky).

Identified on: 4/15/2026

Mode: Standard