mineral

Amethyst

Silicon Dioxide (SiO2) with iron impurities

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 June 24, 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

Forms in hydrothermal veins and hollow volcanic cavities (geodes) when silica-rich fluids cool and crystallize over thousands of years. The purple color is caused by irradiation of iron impurities within the quartz lattice.

Uses & applications

Primarily used in jewelry, as gemstone specimens for collectors, and in decorative ornamental carvings. Historically used for amulets and intaglios.

Geological facts

The name comes from the Greek word 'amethystos', meaning 'not intoxicated', as ancient Greeks believed it could prevent drunkenness. It is the birthstone for February.

Field identification & locations

Identify by its characteristic purple zoning, hexagonal crystal habit, and its ability to scratch glass but not topaz. Commonly found in Brazil, Uruguay, and Madagascar. Collectors look for deep saturation and clarity.

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mineral