mineral
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Hardness: 7 (Mohs scale); Color: Purple, violet; Luster: Vitreous (glassy); Crystal structure: Trigonal/Hexagonal; Cleavage: None/Conchoidal fracture; Specific gravity: 2.65
- Hardness
- 7 (Mohs scale)
- Color
- Purple, violet
- Luster
- Vitreous (glassy)
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Physical properties
Hardness: 7 (Mohs scale); Color: Purple, violet; Luster: Vitreous (glassy); Crystal structure: Trigonal/Hexagonal; Cleavage: None/Conchoidal fracture; Specific gravity: 2.65
Formation & geological history
Formed in hydrothermal veins or as linings in geodes within volcanic cavities. The purple color is caused by natural irradiation of trace iron minerals in the quartz lattice.
Uses & applications
Extensively used in jewelry (faceting and cabochons), crystal healing collections, and as decorative interior display pieces.
Geological facts
Amethyst was considered a 'Cardinal Gem' and was as valuable as diamond until large deposits were discovered in Brazil in the 1700s. Its name comes from the Greek 'amethystos', meaning 'not intoxicated'.
Field identification & locations
Identified by its hexagonal crystal habit, purple color zoning, and hardness. Commonly found in Brazil, Uruguay, Zambia, and South Korea. Look for its distinct purple hue and lack of cleavage.
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