mineral

Amethyst

Silicon dioxide (variant with ferric iron impurities), SiO2

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

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

Identified May 10, 2026More mineral →

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Physical properties

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

Formation & geological history

Formed in hydrothermal veins or cavities (geodes) within igneous rocks like basalt. The purple color is caused by trace amounts of iron being irradiated by natural gamma radiation during or after cooling.

Uses & applications

Primarily used as a gemstone in jewelry (rings, necklaces, earrings), as decorative specimens for collectors, and in spiritual/metaphysical practices.

Geological facts

Amethyst was considered a precious stone on par with diamonds until large deposits were found in Brazil in the 19th century. Its name comes from the Ancient Greek 'amethystos', meaning 'not intoxicated', as it was believed to prevent drunkenness.

Field identification & locations

Identify by its characteristic purple hexagonal crystal habit and glass-like luster. Found abundantly in Brazil, Uruguay, Zambia, and Canada. In the field, look for quartz points in volcanic vugs or riverbeds near volcanic activity.

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