mineral

Amethyst

Amethyst (Silicon Dioxide, SiO2)

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 April 5, 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

Formed in hydrothermal veins and cavities (geodes) of igneous rocks when silica-rich water cools. The purple color comes from irradiation of iron impurities in the quartz. Ages vary by deposit, from millions to billions of years.

Uses & applications

Predominantly used as a gemstone in jewelry, for ornamental carvings, and as a popular collected mineral specimen for its aesthetic beauty and spiritual associations.

Geological facts

Until the discovery of massive deposits in Brazil in the 19th century, amethyst was considered one of the 'Cardinal Gems,' as valuable as diamond, ruby, emerald, and sapphire. It is the birthstone for February.

Field identification & locations

Identify by its characteristic purple color, hexagonal crystal shape, and inability to be scratched by a steel knife. Commonly found in Brazil, Uruguay, Zambia, and South Korea.