mineral

Amethyst

Silicon Dioxide (SiO2) with Iron impurities

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

Identified March 30, 2026More mineral →

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Physical properties

Formation & geological history

Formed in hydrothermal veins or volcanic geodes when silica-rich water cools and crystallizes. The purple color comes from irradiation of trivalent iron (Fe3+) in the quartz structure. These can range from modern formations to millions of years old.

Uses & applications

Primary use in jewelry (gemstone), decorative or ornamental carvings, and widely collected by mineral enthusiasts for metaphysical or aesthetic purposes.

Geological facts

Amethyst was considered a precious stone on par with diamonds until large deposits were found 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 in the field by its distinct purple color, hexagonal crystal points, and lack of cleavage. Common locations include Brazil (Rio Grande do Sul), Uruguay, Zambia, and Ontario, Canada. Collectors should look for deep uniform color and crystal clarity.

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