mineral
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Hardness: 7 (Mohs scale), Color: Purple to violet, Luster: Vitreous (glassy), Crystal Structure: Trigonal/Hexagonal, Cleavage: None (conchoidal fracture), Specific Gravity: 2.65
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Physical properties
Hardness: 7 (Mohs scale), Color: Purple to violet, Luster: Vitreous (glassy), Crystal Structure: Trigonal/Hexagonal, Cleavage: None (conchoidal fracture), Specific Gravity: 2.65
Formation & geological history
Formed in hydrothermal veins or geodes within volcanic rock, typically from silica-rich fluids and trace amounts of iron radiated by surrounding rocks. Often found in Cretaceous or Tertiary deposits.
Uses & applications
Extensively used in jewelry (faceting, beads, cabochons), as decorative crystal clusters for collectors, and in alternative healing practices.
Geological facts
The name comes from the ancient Greek 'amethystos', meaning 'not intoxicated', as it was believed to prevent drunkenness. High-quality deep purple specimens are historically rare and were once considered a 'Cardinal Gem' alongside diamond and ruby.
Field identification & locations
Identify by its purple color and 6-sided prismatic crystal shape ending in a pyramid. Commonly found in Brazil, Uruguay, Zambia, and Ontario. Collectors should look for color saturation and crystal clarity.
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