Amethyst

Physical Properties

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

Formation & Geological History

Formed in igneous and metamorphic rocks, primarily within geodes or cavities in basalt. The purple color is caused by irradiation of iron impurities within the quartz structure.

Uses & Applications

Predominantly used as a gemstone in jewelry (earrings, rings, pendants) and as decorative crystal clusters for collectors and home decor.

Geological Facts

Until the 18th century, amethyst was included in the cardinal, or most valuable, gemstones (along with diamond, sapphire, ruby, and emerald). Ancient Greeks believed it could prevent intoxication.

Field Identification & Locations

Identify by its distinctive purple hue and lack of cleavage. Look for hexagonal crystal terminations in raw specimens. Commonly found in Brazil, Uruguay, Zambia, and South Korea.

Identified on: 4/19/2026

Mode: Standard