The "Oppenheimer Blue", the largest and finest fancy vivid blue diamond ever offered at auction, sold for a world record 56.837 million Swiss francs ($57.6 million) on Wednesday (May 18) after dramatic see-saw bidding, Christie's said. <br /> <br />"It's the most expensive jewel ever sold at auction," Christie's spokeswoman Alexandra Kindermann told. <br /> <br />The rare rectangular-cut stone, which weighs 14.62 carats, previously belonged to Sir Philip Oppenheimer, who controlled the Diamond Syndicate in London. It had a pre-sale estimate of $38 million-$45 million. <br /> <br />The packed Geneva saleroom broke into applause as Rahul Kadakia, Christie's International Head of Jewellery, brought down the hammer after two phone bidders ended a 20-minute battle for the gem. The buyer's identity was not immediately known.
