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Shepard Diamond [G3406]
DiamondDiamonds, like soot, are made of carbon. In a diamond, chains between atoms tightly link to form the hardest material known. In fact, the word diamond comes from the Greek word adamas, which means invincible. Add diamond's fiery brilliance to this extreme hardness and you have a magnificent gem-the April birthstone. Colorless diamonds are few and far between, and valuable as a result. Most diamonds are naturally tinted pale yellow or brown. Fancy diamonds-those with deep shades of yellow, blue, pink, and red-are very rare and highly prized. It is estimated that such fancy colors occur in only one in every 100,000 diamonds.
Hover over color tiles above to learn what this object tells us about the history of the Earth
About this object
Most diamonds are not colorless. In fact, in the formation of most diamonds, a few atoms of nitrogen are substituted for carbon as the crystal grows. These imperfections interact with light to tint the stones yellow or brown. Typically, the more yellow a diamond is, the less it is worth, until the color is intense enough for the stone to be graded a fancy color, such as this intense yellow gem. The 18.30-carat Shepard Diamond from South Africa was acquired in exchange for a small collection of diamonds that had been seized as smuggled goods by the United States Customs Service. The old mine cut diamond is named for the Smithsonian employee who facilitated the exchange, Glen P. Shepard, former Purchasing Officer, in 1958. The Shepard Diamond is on display in the Gem Hall at the Smithsonian’s National Museum of Natural History.
denotes specimens currently on exhibit
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