The Daily Digit is $30.8 million. That's the record price for a 118.28 carat white diamond sold at auction in Hong Kong, Sotheby's announced. The buyer - a secret telephone bidder -according to media reports. The stone mined from southern Africa in 2011 is the size of an egg and weighs as much as a small tangerine, making it the biggest white diamond ever to be auctioned off. Sotheby's chose Hong Kong because it considers it the most important city in the jewelry market.