gemstone
Amethyst
Crystalline Silicon Dioxide with iron impurities (SiO2)
Deep purple to lavender color, vitreous luster, Mohs hardness of 7, trigonal crystal system, no cleavage, conchoidal fracture, specific gravity of 2.65.
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Physical properties
Deep purple to lavender color, vitreous luster, Mohs hardness of 7, trigonal crystal system, no cleavage, conchoidal fracture, specific gravity of 2.65.
Formation & geological history
Formed in hydrothermal veins or as linings within volcanic rock cavities (geodes). The purple color is caused by irradiation and the presence of trace iron impurities (Fe3+).
Uses & applications
Commonly used in jewelry (rings, necklaces), ornamental carvings, and widely collected for metaphysical purposes or as decorative tumbled stones.
Geological facts
Amethyst was considered a precious stone in antiquity, often ranked alongside diamond and ruby, until large deposits were found in Brazil in the 19th century. The name comes from the Greek 'amethystos', meaning 'not intoxicated'.
Field identification & locations
Identified by its distinctive purple hue and hardness being unable to be scratched by steel. Commonly found in Brazil, Uruguay, Zambia, and South Korea. Collectors look for deep saturation and clarity.
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