Amethyst
Silicon Dioxide (SiO2) with iron impurities
Rock Type: mineral

Physical Properties
Hardness: 7 on Mohs scale; Color: Purple, violet, or lavender; Luster: Vitreous (glass-like); Crystal structure: Hexagonal/Trigonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65
Formation & Geological History
Formed in hydrothermal veins and cavities (geodes) of igneous rocks. The purple color is caused by irradiation of iron impurities within the quartz crystal lattice.
Uses & Applications
Primarily used as a gemstone in jewelry, decorative carvings, and as a popular collector's specimen. In industry, it was historically used for seals and intaglios.
Geological Facts
The name comes from the ancient Greek 'amethystos', meaning 'not intoxicated', as it was believed to protect its owner from drunkenness. It is the birthstone for February.
Field Identification & Locations
Identify in the field by its purple hue, lack of cleavage, and hexagonal crystal habit. Common locations include Brazil, Uruguay, Zambia, and South Korea. Collectors should look for deep, uniform color and good transparency.
Identified on: 5/5/2026
Mode: Standard