mineral

Amethyst

Amethyst (Silicon Dioxide, SiO2 + Fe4+ impurities)

Hardness: 7.0 on Mohs scale; Color: Purple, violet, or lavender; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Hardness: 7
Color: Purple, violet, or lavender
Luster: Vitreous (glassy)

Identified March 7, 2026More mineral →

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Physical properties

Hardness: 7.0 on Mohs scale; Color: Purple, violet, or lavender; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Formation & geological history

Formed in hydrothermal veins or geodes when silica-rich water cools in cavities of igneous rocks (primarily basalt). Its purple color is caused by trace amounts of iron and natural irradiation within the earth over millions of years.

Uses & applications

Primary use is in jewelry (cathedral cuts, cabochons) and as decorative ornamental pieces. Highly valued in crystal collecting and the metaphysical community.

Geological facts

Until the 18th century, amethyst was included in the cardinal gemstones alongside diamond, sapphire, ruby, and emerald. Large deposits found in Brazil and Uruguay made it more accessible and shifted its market value.

Field identification & locations

Identify in the field by its distinct purple hue and prismatic 6-sided crystal habits. It can be found globally, with major commercial sources in Brazil, Uruguay, South Korea, Russia, and Zambia. In North America, quality specimens are found in Thunder Bay, Ontario.

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