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Quartz (var. amethyst)

Photo by John Parrish, courtesy of Brenda Smith
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Catalog Number NMNH G11471-00
Locality Four Peaks mine, Arizona, United States
Weight 10 ct

Gift of Brenda Smith in 2014.

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. Most gem amethyst is found in Brazil and Uruguay; however, this gem was mined in Four Peaks, Arizona. This amethyst is a deep violet color with red flashes, a common trait for Four Peaks amethyst. Brenda Smith designed, created, and donated this 18k white gold ring featuring a 10ct amethyst accented with 0.84ctw diamonds. The mounting mimics the scalloped outline of the gem, which is a concave trillion cut, faceted and mined by Darryl Alexander in 2010.


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