mineral

Amethyst (Tumbled/Polished)

Silicon Dioxide (SiO2) with iron impurities

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

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

Identified March 25, 2026More mineral →

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Physical properties

Hardness: 7 (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 hydrothermal veins and hollow geodes within igneous rocks. The purple color results from irradiation of trivalent iron impurities. Geologic ages vary widely depending on the deposit site, ranging from millions to billions of years old.

Uses & applications

Primarily used in jewelry (facets, beads, cabochons), ornamental decoration, and as a popular specimen for mineral collectors. Historically used for intoxication prevention (Greek folklore).

Geological facts

Amethyst was once considered one of the 'Cardinal Gems,' as valuable as diamond, until large deposits were found in Brazil. It is the birthstone for February and the state gemstone of South Carolina.

Field identification & locations

Identify by its distinctive purple hue and ability to scratch glass while resisting a steel file. Commonly found in Brazil, Uruguay, Zambia, and Ontario. Collectors look for deep saturation and clarity.

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