The world's largest known yellow diamond was sold for over $10.9 million

Sotheby's had estimated that the pear-shaped Sun-Drop Diamond would fetch between $11 million and $15 million in Geneva auction. The diamond was sold by New York-based company Cora International, which discovered the jewel in South Africa last year. The color in yellow diamonds is caused by nitrogen impurities trapped within carbon molecules and hardened over the course of millions of years. The sales price doesn't include the auctioneer's commission and any taxes the buyer might have to pay.