Amethyst (Variety of Quartz)

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 hydrothermal veins and volcanic cavities (geodes) when silica-rich solutions cool. The purple color is caused by trace amounts of iron influenced by natural irradiation from the surrounding rock.

Uses & Applications

Primary use in jewelry as a gemstone, lapidary arts, and highly valued as decorative display specimens by collectors and the metaphysical community.

Geological Facts

Amethyst was considered one of the 'Cardinal Gems' until large deposits were found in Brazil. Its name comes from the Ancient Greek 'amethystos', meaning 'not intoxicated', due to a belief that the stone protected its owner from drunkenness.

Field Identification & Locations

Identify in the field by its distinct purple color, lack of cleavage, and ability to scratch glass but not topaz. Commonly found in Brazil, Uruguay, Madagascar, and Arizona, USA.

Identified on: 4/18/2026

Mode: Standard