Fluorite

Physical Properties

Hardness: 4 on Mohs scale; Color: Multi-colored (green, purple, clear); Luster: Vitreous; Crystal structure: Isometric (cubic); Cleavage: Perfect octahedral; Specific gravity: 3.18

Formation & Geological History

Formed in hydrothermal veins often associated with lead and silver ores, or in vugs in limestones and dolostones. It crystallizes from fluids carrying fluorine rising from deep within the crust.

Uses & Applications

Used in the manufacture of steel and aluminum (as a flux), production of hydrofluoric acid, lens coatings for cameras and telescopes, and as a decorative gemstone or collector's specimen.

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'.

Field Identification & Locations

Identify by its distinctive multi-colored banding, cubic crystal habit, and its softness (it can be scratched by a steel knife). Commonly found in China, Mexico, South Africa, and the Illinois-Kentucky district in the USA.

Identified on: 4/13/2026

Mode: Standard