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

Forms in hydrothermal veins and volcanic cavities (geodes). The purple color is caused by irradiation of trivalent iron (Fe3+) impurities in the quartz structure. Most commercial specimens are from the Mesozoic era.

Uses & Applications

Used primarily in jewelry, lapidary arts, and as decorative collector specimens. Historically used for amulets and thought to prevent intoxication.

Geological Facts

The name comes from the Greek word 'amethystos', meaning 'not intoxicated'. Until the 18th century, it was considered one of the five cardinal gemstones alongside diamond, ruby, emerald, and sapphire.

Field Identification & Locations

Identify by its characteristic purple hue, hardness (cannot be scratched by a steel nail), and the absence of cleavage. Found commonly in Brazil, Uruguay, and Zambia.

Identified on: 5/2/2026

Mode: Standard