Amethyst

Amethyst (Silicon Dioxide, SiO2)

Rock Type: mineral

Amethyst

Physical Properties

Hardness: 7 (Mohs scale); Color: Purple, violet; 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, usually from hydrothermal solutions. The purple color comes from iron impurities and natural irradiation over millions of years.

Uses & Applications

Primarily used in jewelry (rings, necklaces), as decorative omaments, and by collectors for metaphysical purposes or aesthetic beauty.

Geological Facts

Amethyst was considered a precious stone in antiquity, often equal in value to diamonds until large deposits were found in Brazil. Its name comes from the Greek 'amethystos', meaning 'not intoxicated'.

Field Identification & Locations

Identify by its characteristic purple color and hexagonal prism crystals if raw; if tumbled, look for transparency and white feather-like inclusions or 'tiger stripe' bands. Commonly found in Brazil, Uruguay, and Zambia.

Identified on: 4/13/2026

Mode: Standard