Amethyst

Physical Properties

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

Formation & Geological History

Formed in hydrothermal veins and basaltic geodes. Its purple color comes from irradiation and the presence of trace iron (Fe3+) in the crystal lattice. Most deposits are found in volcanic rocks, particularly in Brazil and Uruguay.

Uses & Applications

Predominantly used as a gemstone in jewelry, decorative ornaments, and by mineral collectors. Historically used for intaglios and carvings.

Geological Facts

The name comes from the Ancient Greek 'amethystos', meaning 'not intoxicated', as it was once believed to prevent drunkenness. It is the birthstone for February.

Field Identification & Locations

Identify by its distinctive purple color and lack of cleavage (it breaks in smooth curves). Commonly found in geodes or as crystal clusters in basalt cavities. Collectors should look for color saturation and clarity.

Identified on: 4/22/2026

Mode: Standard