mineral

Amethyst (Druzy Cluster)

Silicon Dioxide (SiO2) with Fe3+ impurities

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

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

Identified March 7, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale); Color: Pale lavender to deep violet; 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 within volcanic geodes (vugs). The purple color results from gamma irradiation of trace amounts of iron within the quartz crystal lattice. Specimens range in age from millions to hundreds of millions of years, often found in basaltic lava flows.

Uses & applications

A popular semi-precious gemstone used extensively in jewelry, ornamental carvings, and interior design. In industry, high-quality quartz is used for its piezoelectric properties, though amethyst is primarily valued for aesthetics and collection.

Geological facts

Amethyst was considered one of the 'Cardinal Gems' along with diamond and ruby until large deposits were found in Brazil in the 1700s. Its name comes from the Ancient Greek 'amethystos', meaning 'not intoxicated', as it was believed to prevent drunkenness.

Field identification & locations

Identify in the field by its characteristic purple points, hardness (will scratch glass), and lack of cleavage. Common locations include the Rio Grande do Sul region of Brazil, Uruguay, Madagascar, and Ontario, Canada. Look for it as crusts inside rounded volcanic rocks (geodes).

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