mineral

Amethyst

Silicon dioxide / Violet Quartz (SiO2)

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

Identified April 11, 2026More mineral →

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Physical properties

Hardness: 7 (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 volcanic cavities (geodes). The purple color comes from irradiation, iron impurities, and the presence of trace elements. Age varies by location, with major deposits found in Cretaceous-era basalt.

Uses & applications

Primarily used in jewelry (faceting and cabochons), ornamental carvings, and as a popular specimen for mineral collectors and decorative home decor.

Geological facts

Formerly considered one of the 'Cardinal gems' alongside diamonds and rubies until large deposits were found in Brazil. The name comes from the Greek 'amethystos', meaning 'not intoxicated', as it was once believed to prevent drunkenness.

Field identification & locations

Identify by its hexagonal crystal habit (if points are present), lack of cleavage, and characteristic purple zoning. Common locations include Brazil, Uruguay, Zambia, and Ontario, Canada.