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Smithsonian National Museum of Natural History

Quartz (var. amethyst)

Rwandan amethyst, cut by John Dyer, photo by Priscilla Dyer.
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Catalog Number NMNH G11610-00
Locality Rwanda
Weight 78.3 ct

Gift of Smithsonian Gem and Mineral Collectors in 2017.

Quartz is one of the most abundant minerals in the Earth’s crust. It is composed of the elements silicon and oxygen and in its pure state is colorless. Small amounts of various impurity atoms can produce a range of colors in quartz. Amethyst, the most valuable gem variety of quartz, is purple. Just a few atoms of iron replacing some of the silicon, combined with natural radiation, will cause the purple color. This magnificent 78.30 ct amethyst from Rwanda is a Super Trillion Cut, faceted by award winning gemstone cutter, John Dyer. It is the first amethyst from Rwanda in the National Gem Collection and has a deep rich purple color with flashes of red.



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