mineral

Amethyst

Silicon Dioxide (SiO2) with iron impurities

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

Hardness: 7 on Mohs scale
Color: Purple, violet, or lavender
Luster: Vitreous (glass-like)

Identified May 5, 2026More mineral →

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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.