mineral

Amethyst

Amethyst (SiO2 with iron impurities)

Hardness: 7 on Mohs scale; Color: Purple, violet, or lavender; Luster: Vitreous (glass-like); Crystal Structure: Hexagonal (trigonal); Cleavage: None/Conchoidal fracture; Specific Gravity: 2.65.

Hardness: 7 on Mohs scale
Color: Purple, violet, or lavender
Luster: Vitreous (glass-like)

Identified June 28, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Purple, violet, or lavender; Luster: Vitreous (glass-like); Crystal Structure: Hexagonal (trigonal); Cleavage: None/Conchoidal fracture; Specific Gravity: 2.65.

Formation & geological history

Formed in hydrothermal veins and basaltic geodes. Purple coloration results from gamma irradiation and the presence of trace iron (Fe3+) in the quartz lattice. Most specimens are from the Neoproterozoic to Cretaceous periods.

Uses & applications

Extensively used in jewelry (faceting, cabochons), ornamental decorative pieces, and by collectors. Also high value in metaphysical markets.

Geological facts

Amethyst was considered a 'Cardinal Gem' alongside diamond, ruby, sapphire, and emerald until large deposits were found in Brazil. The name comes from the Ancient Greek 'amethystos', meaning 'not intoxicated'.

Field identification & locations

Identified by its hexagonal prism shape and purple hue. Common locations include Brazil (Rio Grande do Sul), Uruguay, Zambia, and Russia. Look for crystal clusters within vugs or geode shells.