mineral

Amethyst

Amethyst (SiO2 with iron impurities)

Hardness: 7 on Mohs scale; Color: Pale lilac to deep purple; Luster: Vitreous (glassy); Crystal structure: Hexagonal/Trigonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

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

Identified March 22, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Pale lilac 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 and basaltic geodes. Secondary mineralization occurs when silica-rich water fills rock cavities, often during Cenozoic to Cretaceous eras.

Uses & applications

Primarily used in jewelry, ornamental carvings, and gemstone collecting. Historically used for drinking vessels and talismans.

Geological facts

Amethyst was considered a 'Cardinal Gem' until large deposits were found in Brazil. Its name comes from the Ancient Greek 'amethystos', meaning 'not intoxicated', due to a belief it prevented drunkenness.

Field identification & locations

Identify by its distinctive purple color and lack of cleavage. Found in Rio Grande do Sul (Brazil), Uruguay, Zambia, and Ontario. Collectors look for deep violet saturation without visible zoning.