thepracticalgemologist:The Cora Sun-Drop Diamond is the largest known yellow pear-shaped diamond, we
thepracticalgemologist:The Cora Sun-Drop Diamond is the largest known yellow pear-shaped diamond, weighing 110.3 carats. It was sold for $10.9 million at Sotheby’s auction in Geneva and set a world record price for a yellow diamond. It was found in South Africa in 2010 within a kimberlite pipe. Tests show that the diamond was formed from 1 to 3 billion years ago. Nitrogen impurities in the carbon crystal structure give the diamond its yellow color as they modify light, absorbing the blue part of the visible spectrum.The stone was cut by New York based Cora International. The Sun-Drop was unveiled to the world at London’s Natural History Museum where it was exhibited in the famous ‘Vault Gallery’ from February through August 2011. In November 2011, it was sold at an auction to an anonymous phone bidder. -- source link