mineral

Amethyst

Amethyst (Silicon Dioxide - SiO2 with Iron impurities)

Hardness: 7 (Mohs scale), Color: Various shades of purple/violet, Luster: Vitreous (glass-like), Crystal Structure: Hexagonal/Trigonal, Cleavage: None (conchoidal fracture), Specific Gravity: 2.65

Identified April 5, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale), Color: Various shades of purple/violet, Luster: Vitreous (glass-like), Crystal Structure: Hexagonal/Trigonal, Cleavage: None (conchoidal fracture), Specific Gravity: 2.65

Formation & geological history

Formed in hydrothermal veins or as geodes in igneous volcanic rocks. The purple color is caused by irradiation of trivalent iron (Fe3+) in the crystal structure. Most commercial specimens are from the Cretaceous period in South America.

Uses & applications

Extensively used in jewelry (faceting and cabochons), ornamental decoration, and as a popular specimen for mineral collectors and metaphysical practitioners.

Geological facts

Until the 18th century, amethyst was included in the cardinal gemstones alongside diamond, ruby, emerald, and sapphire. Huge deposits found in Brazil made it more accessible and affordable.

Field identification & locations

Identify in the field by its distinct purple hue and prismatic hexagonal crystals. Commonly found in Brazil, Uruguay, Zambia, and South Korea. Collectors look for deep 'Siberian' purple with red flashes.

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