mineral

Amethyst

Silicon Dioxide with Iron impurities (SiO2)

Hardness: 7 (Mohs scale); Color: Pale lilac to deep purple; Luster: Vitreous (glassy); Crystal Structure: Hexagonal/Trigonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 (Mohs scale)
Color: Pale lilac to deep purple
Luster: Vitreous (glassy)

Identified March 23, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale); Color: Pale lilac to deep purple; Luster: Vitreous (glassy); Crystal Structure: Hexagonal/Trigonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed in hydrothermal veins or as linings inside volcanic geodes. The purple color is caused by irradiation and the presence of trace iron impurities within the silicon dioxide crystal lattice.

Uses & applications

Extensively used in jewelry (faceting and cabochons), ornamental carvings, and as a popular mineral specimen for collectors. Historically used to ward off intoxication.

Geological facts

The name comes from the Ancient Greek word 'amethystos', meaning 'not intoxicated'. Until the 18th century, it was considered one of the 'Cardinal Gems' along with diamonds and rubies, before large deposits were found in South America.

Field identification & locations

Identify by its purple hue and typical hexagonal crystal points (if uncut). Found globally in Brazil, Uruguay, Zambia, and Canada. Collectors should look for even color distribution and transparency.

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