Amethyst

Physical Properties

Hardness: 7 (Mohs scale); Color: Purple, violet, or lavender; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & Geological History

Formed in hydrothermal veins or as linings in geodes. The purple color is caused by natural irradiation of trace iron impurities within the quartz crystal lattice. Found in volcanic rocks and metamorphic environments.

Uses & Applications

Primarily used in jewelry (faceting and cabochons), decorative home decor, and as a popular specimen for mineral collectors.

Geological Facts

Amethyst was once considered one of the 'Cardinal Gems' alongside diamond, ruby, sapphire, and emerald until large deposits were found in Brazil. Its name comes from the Ancient Greek 'amethystos', meaning 'not intoxicated', as it was believed to protect the wearer from drunkenness.

Field Identification & Locations

Identify by its characteristic purple color, hexagonal crystal habit (if points are present), and inability to be scratched by a steel knife. Common locations include Brazil, Uruguay, Africa (Zambia), and Arizona, USA.

Identified on: 4/28/2026

Mode: Standard