gemstone
Amethyst (Lab-created or facet-grade)
Silicon Dioxide (SiO2) with iron impurities
Hardness 7.0 on Mohs scale, pale purple to lilac color, vitreous luster, hexagonal crystal system, conchoidal fracture, specific gravity 2.65.
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Physical properties
Hardness 7.0 on Mohs scale, pale purple to lilac color, vitreous luster, hexagonal crystal system, conchoidal fracture, specific gravity 2.65.
Formation & geological history
Formed in hydrothermal veins or volcanic cavities (geodes) when silica-rich water cools. The purple color is caused by trace iron irradiated by natural gamma rays over millions of years.
Uses & applications
Primary use is in fine and fashion jewelry (rings, earrings, necklaces). Frequently used as a birthstone and in metaphysical collecting.
Geological facts
Amethyst was considered a 'Cardinal Gem' until the 18th century, ranked alongside diamonds and rubies in value until huge deposits were found in Brazil. The name comes from the Greek 'amethystos', meaning 'not drunken'.
Field identification & locations
Identify by its characteristic purple tint and lack of cleavage. In jewelry settings, check for clarity and uniform color. Commonly found in Brazil, Uruguay, and Africa.
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