Amethyst

Physical Properties

Hardness: 7 (Mohs scale); Color: Purple, violet, to deep reddish-purple; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Formation & Geological History

Formed in hydrothermal veins and basaltic geodes. The purple color comes from gamma irradiation of trace trivalent iron (Fe3+) in the quartz crystal structure as it grows from silica-rich groundwater. Often found in volcanic cavities.

Uses & Applications

Predominantly used as a gemstone in jewelry, for decorative items, and as a popular specimen for mineral collectors and practitioners of crystal healing.

Geological Facts

Amethyst is the birthstone for February. The name comes from the Ancient Greek 'amethystos', meaning 'not intoxicated', as it was believed to protect its owner from drunkenness.

Field Identification & Locations

Look for purple pyramidal crystal terminations on a white to gray matrix. It is commonly found in Brazil, Uruguay, Madagascar, and the United States (notably Arizona and Georgia). Identification can be confirmed by its hardness and absence of cleavage.

Identified on: 5/5/2026

Mode: Standard