mineral

Amethyst (Rough Crystal)

Silicon Dioxide (SiO2 with ferric iron impurities)

Hardness: 7 on Mohs scale; Color: Pale lavender to deep violet; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: None/Conchoidal fracture; Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Pale lavender to deep violet
Luster: Vitreous (glassy)

Identified March 28, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Pale lavender to deep violet; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: None/Conchoidal fracture; Specific Gravity: 2.65

Formation & geological history

Formed in hydrothermal veins and volcanic cavities (geodes). The purple color results from irradiation of trivalent iron (Fe3+) within the quartz lattice. Most commercial specimens date from the Cretaceous period.

Uses & applications

Predominantly used as a gemstone in jewelry, for decorative carvings, and as popular specimens for mineral collectors and metaphysical practitioners.

Geological facts

Until the 18th century, amethyst was included in the cardinal gemstones along with diamond, ruby, and emerald. Ancient Greeks believed it could prevent intoxication.

Field identification & locations

Identify in the field by its distinct purple hue, glass-like luster, and lack of cleavage planes. Found globally with major deposits in Brazil, Uruguay, Zambia, and Ontario, Canada.

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