mineral
Amethyst
Amethyst (Silicon Dioxide, SiO2 with iron impurities)
Hardness: 7 on Mohs scale; Color: Purple, violet, or lavender; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: None/Conchoidal fracture; Specific gravity: 2.65
- Hardness
- 7 on Mohs scale
- Color
- Purple, violet, or lavender
- Luster
- Vitreous (glassy)
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Physical properties
Hardness: 7 on Mohs scale; Color: Purple, violet, or lavender; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: None/Conchoidal fracture; Specific gravity: 2.65
Formation & geological history
Formed in hydrothermal veins or geodes when silica-rich water fills cavities in volcanic rocks. The purple color is caused by irradiation of iron impurities within the quartz crystal lattice. Formations can range from thousands to millions of years old.
Uses & applications
Primarily used as a gemstone in jewelry (rings, necklaces, earrings), as decorative specimens for collectors, and in metaphysical practices.
Geological facts
Amethyst was once considered one of the 'Cardinal gems' and was more valuable than diamonds until large deposits were found in Brazil in the 19th century. The name comes from the Greek word 'amethystos', meaning 'not intoxicated'.
Field identification & locations
Identify by its characteristic purple color, 7-level hardness (will scratch glass), and lack of cleavage. Commonly found in Brazil, Uruguay, Zambia, and South Korea. Field identification involves looking for crystal points (prisms) in geode cavities.
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