Amethyst

Physical Properties

Hardness: 7 on Mohs scale; Color: Purple, violet, to pale lavender; Luster: Vitreous/glassy; Crystal Structure: Hexagonal (trigonal); Cleavage: None/conchoidal fracture; Specific Gravity: 2.65.

Formation & Geological History

Formed in hydrothermal veins or as linings in geodes. The purple color comes from irradiation of iron impurities within the quartz crystal structure. Common in volcanic rocks and pegmatites.

Uses & Applications

Predominantly used as a gemstone in jewelry, for ornamental carvings, and widely collected by crystal enthusiasts and geologists.

Geological Facts

Amethyst was once considered one of the 'cardinal gems' alongside diamond and ruby, until large deposits were found in Brazil. The name comes from the Greek 'amethystos,' meaning 'not intoxicated.'

Field Identification & Locations

Identify in the field by its distinct purple hue and hexagonal prismatic crystal habit. Commonly found in Brazil, Uruguay, and various parts of the United States and Africa.

Identified on: 4/26/2026

Mode: Standard