mineral

Amethyst

Silicon Dioxide (SiO2) with iron impurities

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

Hardness: 7 (Mohs scale)
Color: Deep purple to pale lavender
Luster: Vitreous (glassy)

Identified April 13, 2026More mineral →

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Physical properties

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

Formation & geological history

Formed in hydrothermal veins and basaltic geodes. The purple color is caused by gamma irradiation of trivalent iron impurities in the quartz structure. Most specimens are found in volcanic rocks and can range from 100 to over 500 million years old.

Uses & applications

Primary use in jewelry, lapidary arts, and as a popular collector's mineral. Also used in spiritual and metaphysical practices.

Geological facts

Amethyst was considered a precious stone equal in value to diamonds until large deposits were discovered in Brazil in the 19th century. The name comes from the Greek word 'amethystos', meaning 'not intoxicated', as it was believed to prevent drunkenness.

Field identification & locations

Identify in the field by its hexagonal crystal habit (if not tumbled), purple color, and lack of cleavage. Common locations include Brazil, Uruguay, Zambia, and Canada. Look for crystal-lined cavities (geodes) in volcanic regions.

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