Amethyst (Faceted)

Physical Properties

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

Formation & Geological History

Formed in geodes or veins when silica-rich hydrothermal fluids precipitate in cavities of igneous or metamorphic rocks. The purple color is caused by gamma irradiation of trace amounts of iron within the quartz structure.

Uses & Applications

Primary use is in jewelry (rings, pendants, earrings) and as a highly popular collector's mineral specimen. Historically used as an amulet to prevent intoxication.

Geological Facts

Amethyst is the birthstone for February. The name comes from the Greek 'amethystos', meaning 'not drunken', as the ancient Greeks believed the stone could prevent alcohol poisoning and drunkenness.

Field Identification & Locations

Identify by its characteristic purple color, lack of cleavage, and ability to scratch glass. Faceted stones should be checked for color zoning and inclusions like 'tiger stripes' under magnification. Commonly found in Brazil, Uruguay, and Zambia.

Identified on: 4/27/2026

Mode: Standard