Mineral

Amethyst

Silicon Dioxide (SiO2) with iron impurities

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

Hardness: 7 on Mohs scale
Color: Purple to violet due to iron radiation
Luster: Vitreous (glassy)

Identified March 18, 2026More mineral →

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Physical properties

Formation & geological history

Forms in geothermal environments, often inside igneous volcanic cavities (geodes) or hydrothermal veins. The purple color is caused by the irradiation of trivalent iron impurities within the quartz crystal lattice.

Uses & applications

Primarily used as a gemstone in jewelry (rings, necklaces), as decorative specimens for collectors, and in alternative healing practices. High-purity quartz is used in electronics, though amethyst itself is usually kept for its aesthetic value.

Geological facts

Ancient Greeks believed amethyst could prevent intoxication, which is why its name comes from the Greek word 'amethystos' meaning 'not intoxicated.' It was once considered one of the 'Cardinal Gems' along with diamond and ruby before large deposits were found in Brazil.

Field identification & locations

Identify in the field by its distinct purple color, 6-sided crystal habit (if points are present), and inability to be scratched by a steel knife. Common locations include Brazil, Uruguay, Zambia, and Ontario, Canada.

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