mineral

Amethyst

Silicon dioxide with iron impurities (SiO2 + Fe3+)

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

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

Identified April 12, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale); Color: Pale violet 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 in geodes. Most amethysts occur in cavity linings of volcanic rocks (basalt). The purple color comes from gamma irradiation of trace iron impurities. Formation can occur over millions of years.

Uses & applications

Primarily used in jewelry (faceting and cabochons), as decorative specimens for collectors, and in alternative healing practices (metaphysical crystals). High-quality stones are valuable gemstones.

Geological facts

The name comes from the Ancient Greek 'amethystos', meaning 'not intoxicated', as it was believed to protect the wearer from drunkenness. It was once considered one of the 'Cardinal gems' until large deposits were found in Brazil.

Field identification & locations

Identify by its distinctive purple color and hexagonal prism crystal habits. Often found in geodes. Common locations include Brazil, Uruguay, Zambia, and South Korea. It will scratch glass but cannot be scratched by a steel pocket knife.

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