mineral

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Hardness: 7.0 Mohs scale; Color: Pale lilac to deep purple; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7
Color: Pale lilac to deep purple
Luster: Vitreous (glassy)

Identified March 15, 2026More mineral →

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Physical properties

Hardness: 7.0 Mohs scale; Color: Pale lilac to deep purple; 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 inside volcanic geodes. The purple color results from irradiation of trivalent iron impurities (Fe3+) within the quartz structure. Most commercial specimens are from the Cretaceous period in basaltic flows.

Uses & applications

Predominantly used as a gemstone in jewelry, for decorative home decor objects, and as a popular specimen for mineral collectors and metaphysical practitioners.

Geological facts

The name comes from the ancient Greek word 'amethystos', meaning 'not intoxicated', as it was believed to protect its owner from drunkenness. It was once considered one of the 'Cardinal Gems' along with diamond and ruby until large deposits were found in Brazil.

Field identification & locations

Identify by its characteristic purple color and hexagonal prism crystal habits. Commonly found in Brazil, Uruguay, Zambia, and South Korea. In the field, look for quartz-lined cavities within igneous rocks or rounded volcanic 'bombs' (geodes).

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