Amethyst

Physical Properties

Hardness: 7 (Mohs scale); Color: Purple, violet, or lavender; Luster: Vitreous/Glassy; Crystal structure: Trigonal/Hexagonal prism; Cleavage: None/Conchoidal fracture; Specific gravity: 2.65

Formation & Geological History

Formed within volcanic rock geodes or hydrothermal veins through the deposition of silica-rich water. Its purple color is caused by gamma irradiation of trivalent iron (Fe3+) in the quartz structure. Most specimens range from recent to hundreds of millions of years old.

Uses & Applications

Primarily used in jewelry (faceting and cabochons), ornamental decoration, and as a popular metaphysical or collector's specimen.

Geological Facts

Amethyst was once considered one of the 'cardinal gems' along with diamond and ruby until large deposits were found in Brazil. The name comes from the Ancient Greek 'amethystos', meaning 'not intoxicated', as it was believed to prevent drunkenness.

Field Identification & Locations

Identify by its characteristic purple hue, hexagonal crystal habits (when raw), and hardness. Often found in pockets of basalt or granite. Common locations include Brazil, Uruguay, Zambia, and Ontario, Canada.

Identified on: 4/27/2026

Mode: Standard