mineral

Amethyst

Silicon Dioxide (SiO2) with Iron impurities

Hardness: 7 on the Mohs scale; Color: Purple to violet; Luster: Vitreous (glassy); Crystal Structure: Hexagonal/Trigonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on the Mohs scale
Color: Purple to violet
Luster: Vitreous (glassy)

Identified March 25, 2026More mineral →

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Physical properties

Hardness: 7 on the Mohs scale; Color: Purple to violet; 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. Usually occurs when silica-rich water enters gas cavities in cooling lava. Most deposits date from the Cretaceous period to the present.

Uses & applications

Primarily used as a gemstone in jewelry (rings, pendants, earrings), as decorative specimens for collectors, and in metaphysical practices.

Geological facts

The purple color comes from irradiation of trivalent iron (Fe3+) in the quartz structure. It was historically considered as valuable as diamonds until large deposits were discovered in Brazil in the 19th century.

Field identification & locations

Identify by its characteristic purple color and 7-Mohs hardness (will scratch glass). Commonly found in Brazil, Uruguay, Zambia, and South Korea. Collectors should look for deep 'Siberian' purple hues with red or blue flashes.

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