gemstone

Amethyst

Quartz (Silicon Dioxide, SiO2)

Hardness: 7 on the Mohs scale. Color: Purple to violet, sometimes with lighter or darker stripes. Luster: Vitreous (glassy). Crystal structure: Trigonal (hexagonal crystal system). Cleavage: None, exhibits conchoidal fracture. Specific gravity: 2.65.

Hardness: 7 on the Mohs scale
Color: Purple to violet, sometimes with lighter or darker stripes
Luster: Vitreous (glassy)

Identified August 3, 2026More gemstone →

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Physical properties

Formation & geological history

Formed in low-temperature hydrothermal veins, as well as cavities (vugs and geodes) in basaltic volcanic rocks, where silica-rich fluids deposit quartz crystals over millions of years.

Uses & applications

Widely used as a gemstone in jewelry, for ornamental carvings, and as a popular mineral specimen for crystal healing and mineral collectors.

Geological facts

Amethyst is the purple variety of quartz. Its distinctive color is caused by irradiation, iron impurities, and the presence of other transition metal elements.

Field identification & locations

Can be identified by its characteristic purple color, vitreous luster, and hardness of 7 which allows it to scratch glass easily. Common localities include Brazil, Uruguay, Zambia, and the USA.