mineral

Amethyst

Silicon dioxide with iron impurities (SiO2)

Hardness: 7 (Mohs scale); Color: Purple, violet, or lavender; Luster: Vitreous (glassy); Crystal Structure: Hexagonal/Trigonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 (Mohs scale)
Color: Purple, violet, or lavender
Luster: Vitreous (glassy)

Identified January 24, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale); Color: Purple, violet, or lavender; Luster: Vitreous (glassy); Crystal Structure: Hexagonal/Trigonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed in hydrothermal veins or volcanic geodes when silica-rich water deposits crystals inside rock cavities. The purple color is caused by irradiation of trivalent iron (Fe3+) within the quartz structure.

Uses & applications

Primarily used in jewelry (as gemstones), decorative carvings, and as a popular mineral specimen for collectors. Historically believed to prevent intoxication.

Geological facts

Amethyst was considered one of the five cardinal gemstones until the discovery of large deposits in Brazil in the 1700s. Its name comes from the Greek word 'amethystos', meaning 'not intoxicated'.

Field identification & locations

Identify in the field by its distinct purple hue and quartz-like hexagonal crystal points. Commonly found in Brazil, Uruguay, Zambia, and South Korea. Collectors should look for even color distribution and transparency.

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