mineral

Amethyst

Amethyst (Silicon Dioxide, SiO2 with Iron impurities)

Hardness: 7 on Mohs scale; Color: Purple to deep violet; Luster: Vitreous (glass-like); Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65.

Hardness: 7 on Mohs scale
Color: Purple to deep violet
Luster: Vitreous (glass-like)

Identified April 13, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Purple to deep violet; Luster: Vitreous (glass-like); Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65.

Formation & geological history

Formed in hydrothermal veins or as linings in basaltic geodes. Its purple color is caused by natural irradiation of trace trivalent iron (Fe3+) impurities. Formation can range from millions to hundreds of millions of years ago depending on the host rock.

Uses & applications

Primary use in jewelry, lapidary arts, and as common collector specimens. Historically used for amulets and carvings.

Geological facts

The name comes from the Ancient Greek 'amethystos', meaning 'not intoxicated', as it was believed to prevent drunkenness. It was considered one of the Cardinal gems until large deposits were found in Brazil in the 19th century.

Field identification & locations

Identify by its purple hue, hexagonal point structure, and lack of visible cleavage. Commonly found in Brazil, Uruguay, Zambia, and Canada. A high-quality field indicator is its ability to scratch glass easily.

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