mineral

Amethyst

Silicon Dioxide (SiO2) with iron impurities

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 May 9, 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

Forms in geothermal environments, primarily as druzy linings within volcanic geodes or cavities. The purple hue is caused by irradiation of trivalent iron impurities within the quartz crystal lattice.

Uses & applications

Extensively used in jewelry (faceting and cabochons), as ornamental decorative pieces, and by collectors for its aesthetic crystal formations.

Geological facts

The name comes from the Ancient Greek 'amethystos', meaning 'not intoxicated', as it was believed to protect its owner from drunkenness. It was once considered one of the five cardinal gemstones until large deposits were found in Brazil.

Field identification & locations

Identified by its distinctive purple color and hexagonal crystal terminations. Commonly found in Brazil, Uruguay, and Madagascar. Collectors look for deep 'Siberian' purple hues and lack of zoning.