mineral

Amethyst

SiO2 (Silicon Dioxide with iron impurities and irradiation)

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

Hardness: 7 on Mohs scale
Color: Purple to deep violet
Luster: Vitreous (glassy)

Identified March 20, 2026More mineral →

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Physical properties

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

Formation & geological history

Formed in hydrothermal veins or as geodes in igneous rocks. The purple color results from natural irradiation and trace amounts of iron (Fe3+) in the silica lattice. Most specimens are from the Mesozoic or Cenozoic eras.

Uses & applications

Primary use is in jewelry (faceted gemstones, beads, cabochons), decorative ornaments, and as rough specimens for collectors and metaphysical markets.

Geological facts

Amethyst was considered one of the 'Cardinal Gems' until the discovery of large deposits in Brazil in the 19th century. Its name comes from the Ancient Greek 'amethystos', meaning 'not intoxicated', as it was believed to prevent drunkenness.

Field identification & locations

Identify by its characteristic purple color and hexagonal prism crystal habits. In the field, look for geodes in volcanic basalt. Major locations include Brazil, Uruguay, Zambia, and South Korea.

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