mineral

Amethyst

Amethyst (variety of Quartz, SiO2)

Hardness: 7 on Mohs scale; Color: light to dark purple; Luster: vitreous (glassy); Crystal structure: Trigonal/Hexagonal; Cleavage: none (conchoidal fracture); Specific gravity: 2.65

Hardness: 7 on Mohs scale
Color: light to dark purple
Luster: vitreous (glassy)

Identified March 23, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: light to dark purple; Luster: vitreous (glassy); Crystal structure: Trigonal/Hexagonal; Cleavage: none (conchoidal fracture); Specific gravity: 2.65

Formation & geological history

Formed in hydrothermal veins and granite vugs or as geodes in volcanic basalts. The purple color is caused by natural irradiation of iron impurities within the silicon dioxide crystal lattice. Common in post-Cretaceous volcanic formations.

Uses & applications

Primarily used as a semi-precious gemstone in jewelry (rings, beads, pendants) and for ornamental carvings. It is also a popular specimen for mineral collectors and a central stone in holistic/metaphysical practices.

Geological facts

Until the discovery of large deposits in Brazil in the 1700s, amethyst was considered one of the 'cardinal gems' along with diamond, ruby, sapphire, and emerald. Its name comes from the Greek 'amethystos', meaning 'not drunken', as it was believed to prevent intoxication.

Field identification & locations

Identify by its characteristic purple hexonal prisms or purple translucency in tumbled beads. It can be found globally with major deposits in Brazil, Uruguay, Zambia, and South Korea. Look for its ability to scratch glass (hardness test) and its lack of cleavage.