mineral

Amethyst

Amethyst (Silicon Dioxide, SiO2)

Hardness: 7 on Mohs scale; Color: Purple, violet, to lavender; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

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

Identified April 5, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Purple, violet, to lavender; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed in hydrothermal veins or as linings in geodes. It develops when silica-rich fluids permeate cavities in volcanic or sedimentary rocks, often following prehistoric volcanic activity. Colors are caused by irradiation, iron impurities, and the presence of trace elements.

Uses & applications

Primarily used in jewelry (as a gemstone), ornamental carvings, and as a popular mineral specimen for collectors. Historically used for amulets and decorative vessels.

Geological facts

Ancient Greeks believed amethyst could prevent intoxication. The word comes from the Greek 'amethystos', meaning 'not intoxicated'. It is the birthstone for February.

Field identification & locations

Identify in the field by its distinct purple hue, hexagonal crystal form with six-sided points, and hardness that can scratch glass but not topaz. Common locations include Brazil, Uruguay, Zambia, and South Korea.