mineral

Amethyst

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs), Color: Purple to violet, Luster: Vitreous/Glassy, Crystal Structure: Trigonal/Hexagonal, Cleavage: None (conchoidal fracture), Specific Gravity: 2.65

Identified June 9, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs), Color: Purple to violet, Luster: Vitreous/Glassy, Crystal Structure: Trigonal/Hexagonal, Cleavage: None (conchoidal fracture), Specific Gravity: 2.65

Formation & geological history

Formed in hydrothermal veins and basaltic cavities (geodes) through the precipitation of silica from groundwater; color is derived from iron impurities and natural irradiation over millions of years.

Uses & applications

Highly valued as a gemstone for jewelry, ornamental carvings, and a popular specimen for mineral collectors and metaphysical practitioners.

Geological facts

Until the 18th century, amethyst was considered one of the 'cardinal gems' in a high-value class along with diamond, ruby, sapphire, and emerald. It is the birthstone for February.

Field identification & locations

Identify by its characteristic purple color and six-sided crystal points. Can be found globally, with major deposits in Brazil and Uruguay. Collectors should look for deep, uniform color and clarity.