mineral

Amethyst

SiO2 (Silicon Dioxide with Iron impurities)

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

Identified May 29, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale), Color: Purple to deep violet, 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. The purple color is caused by irradiation of trivalent iron impurities. Commonly found in volcanic rocks (basalt) and metamorphic rocks.

Uses & applications

Primarily used as a gemstone in jewelry, for decorative items, and highly valued by mineral collectors for its metaphysical associations and aesthetic beauty.

Geological facts

Until the 18th century, amethyst was included in the cardinal (most valuable) gemstones, along with diamond, sapphire, ruby, and emerald, before large deposits were found in Brazil.

Field identification & locations

Identify by its distinctive purple color and lack of cleavage. It is commonly found in Brazil, Uruguay, Zambia, and South Korea. Collectors should look for depth of color and clarity.