mineral

Amethyst

Amethyst (Silicon Dioxide - SiO2)

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

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

Identified March 22, 2026More mineral →

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Physical properties

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

Formation & geological history

Formed in igneous and metamorphic rocks, often within geodes or hydrothermal veins as silica-rich water cools. It can range in age from millions to hundreds of millions of years old, appearing in volcanic basalt cavities.

Uses & applications

Primarily used in jewelry (cabochons and faceted gems), ornamental carvings, and as a popular specimen for rock and mineral collectors.

Geological facts

The purple color comes from iron impurities and irradiation. Historically, the ancient Greeks believed it could prevent intoxication; the name comes from 'amethystos,' meaning 'not intoxicated.'

Field identification & locations

Identify in the field by its distinct purple hue and ability to scratch glass (glass is usually 5.5). Common locations include Brazil, Uruguay, Zambia, and South Korea. Collectors should look for vibrant color saturation and clarity.