Amethyst

Physical Properties

Hardness: 7 on 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 cavities (geodes) of igneous rocks, particularly basalt, through hydrothermal activity. The purple color is caused by gamma irradiation of iron impurities within the quartz lattice. Most common in volcanic formations.

Uses & Applications

Predominantly used as a gemstone in jewelry (rings, necklaces), as a collector's mineral, and in metaphysical or spiritual practices.

Geological Facts

Amethyst was considered one of the 'Cardinal Gems' along with diamond, sapphire, ruby, and emerald 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 distinct purple hue and lack of cleavage. In the field, look for hexagonal prism crystals inside hollow geodes or as veins in rock. Common locations include Brazil, Uruguay, Zambia, and Ontario.

Identified on: 4/25/2026

Mode: Standard