mineral

Amethyst

Silicon Dioxide (SiO2) with iron impurities

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

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

Identified May 21, 2026More mineral →

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Physical properties

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

Formation & geological history

Forms in geodes or cavities within igneous volcanic rocks such as basalt. The purple color is caused by irradiation of trivalent iron impurities within the quartz crystal lattice.

Uses & applications

Primarily used in jewelry (faceting and cabochons), decorative home decor, and as a popular specimen for mineral collectors.

Geological facts

Amethyst was once considered one of the 'Cardinal Gems' alongside diamond, ruby, emerald, and sapphire until large deposits were found in Brazil. Its name comes from the Greek word 'amethystos,' meaning 'not intoxicated.'

Field identification & locations

Identify by its purple hue, hexagonal crystal habit, and its ability to scratch glass but remain unscratched by steel. Commonly found in Brazil, Uruguay, Zambia, and South Korea. Collectors should look for saturated color and clarity.