mineral

Amethyst

Amethyst (Silicon Dioxide - SiO2 with iron impurities)

Hardness: 7 on Mohs scale; Color: Purple, violet, or lavender; Luster: Vitreous (glassy); Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

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

Identified March 20, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Purple, violet, or lavender; Luster: Vitreous (glassy); Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Formation & geological history

Formed in hydrothermal veins or inside igneous geodes when silica-rich water cools and crystallizes. The purple color is caused by irradiation of trivalent iron (Fe3+) in the quartz structure. These can range from millions to over a billion years old.

Uses & applications

Primarily used in jewelry, ornamental carvings, and as a popular semi-precious gemstone for collectors. Also used for holistic or spiritual purposes in some cultures.

Geological facts

The name comes from the Ancient Greek word 'amethystos', meaning 'not intoxicated', as it was believed to protect the wearer from drunkenness. It was once considered one of the five cardinal gemstones alongside ruby and emerald before large deposits were found in South America.

Field identification & locations

Identify by its purple hue, 6-sided crystal habit (if not tumbled), and inability to be scratched by a steel blade. Commonly found in Brazil, Uruguay, Zambia, and Ontario. Collectors look for deep saturation and clarity.

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