gemstone

Amethyst

Quartz (Silicon Dioxide with Iron impurities), SiO2

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

Hardness: 7 Mohs
Color: Purple to deep violet
Luster: Vitreous

Identified July 19, 2026More gemstone →

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Physical properties

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

Formation & geological history

Formed in hydrothermal veins or geodes within volcanic rocks when silica-rich water cools and crystallizes; color is caused by irradiation and iron impurities.

Uses & applications

Primarily used in jewelry making, ornamental carvings, and as a popular specimen for mineral collectors.

Geological facts

Amethyst was considered a precious stone equal to Diamond or Ruby until large deposits were found in Brazil in the 19th century. Its name comes from the Greek 'amethystos', meaning 'not drunken'.

Field identification & locations

Identify by its characteristic purple color and hexagonal crystal habit if raw; if tumbled, look for subtle color zoning. Common in Brazil, Uruguay, Zambia, and Ontario.

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