mineral

Amethyst

Amethyst (Silicon Dioxide with Iron impurities, SiO2)

Hardness: 7 on Mohs scale; Color: Purple, violet, to deep reddish-purple; Luster: Vitreous (glass-like); Crystal structure: Hexagonal (trigonal); Cleavage: None/Conchoidal fracture; Specific gravity: 2.65

Hardness: 7 on Mohs scale
Color: Purple, violet, to deep reddish-purple
Luster: Vitreous (glass-like)

Identified March 16, 2026More mineral →

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Physical properties

Formation & geological history

Formed in hydrothermal veins or as linings within volcanic rock cavities (geodes). The purple color results from irradiation of trivalent iron impurities within the quartz crystal lattice. Found in rocks ranging from millions to billions of years old.

Uses & applications

Primarily used as a gemstone in jewelry (rings, necklaces), as decorative specimens for collectors, and in metaphysical/holistic practices.

Geological facts

Until the discovery of massive deposits in Brazil in the 19th century, amethyst was considered one of the 'Cardinal Gems' alongside diamond, ruby, sapphire, and emerald. Its name comes from the Greek 'amethystos', meaning 'not intoxicated'.

Field identification & locations

Identify in the field by its purple hue, hexagonal crystal habit (six-sided points), and ability to scratch glass. Commonly found in Brazil, Uruguay, Zambia, and Ontario, Canada. Look for vugs in basaltic lava or granite.

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