mineral

Amethyst

SiO2 (Silicon Dioxide 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 25, 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 or as linings in geodes. The purple color is caused by gamma irradiation of trivalent iron impurities in the quartz structure. Most specimens range from late Cretaceous to recent.

Uses & applications

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

Geological facts

Until the 18th century, amethyst was included in the cardinal gemstones, alongside diamond, ruby, sapphire, and emerald. Massive deposits discovered in Brazil significantly lowered its market value.

Field identification & locations

Identify by its characteristic purple color and ability to scratch glass. In the field, look for hexagonal prisms or geodes in volcanic rock environments such as basalt. Major sources include Brazil, Uruguay, and Zambia.