mineral

Amethyst

Silicon Dioxide (SiO2) with iron impurities

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

Identified March 14, 2026More mineral →

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Physical properties

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

Formation & geological history

Formed in hydrothermal veins or cavities (geodes) of igneous rocks when silica-rich water cools. The purple color is caused by irradiation and the presence of trace iron minerals. Geological age varies by deposit, ranging from millions to hundreds of millions of years.

Uses & applications

Primary use in jewelry (gemstones), ornamental carvings, and high-quality mineral collections. Historically used for drinking vessels and talismans.

Geological facts

Ancient Greeks believed amethyst could prevent intoxication, which is why its name comes from the Greek word 'amethystos' meaning 'not intoxicated'. It is the birthstone for February.

Field identification & locations

Identify by its distinctive purple hue and hexagonal crystal faces. Commonly found in Brazil, Uruguay, Zambia, and South Korea. In the field, look for purple crystals inside drab-looking basaltic geodes or appearing as tumbled water-worn pebbles in stream beds.

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