mineral

Amethyst

Silicon dioxide with iron impurities (SiO2)

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 July 2, 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

Formed in hydrothermal veins and basaltic geodes through volcanic activity. The purple color is caused by trace amounts of iron radiated by natural gamma rays over millions of years.

Uses & applications

Primarily used in jewelry, as decorative collector specimens, and in metaphysical practices.

Geological facts

Until the 18th century, amethyst was included in the cardinal gemstones along with diamond, ruby, emerald, and sapphire, but it lost much of its value after the discovery of large deposits in Brazil.

Field identification & locations

Identify in the field by its hexagonal crystal habit and purple hue. Found commonly in Brazil, Uruguay, Zambia, and South Korea. Collectors should look for deep purple saturation and clarity.