A ring containing a rare 5.16 carat pear shaped blue diamond is displayed for a photograph at Sotheby's in New York, U.S., on Thursday, March 4, 2010. The 5.16 carat flawless fancy vivid blue diamond, formerly part of the De Beers Millennium Jewels Collection, is the first blue diamond from the collection to appear at auction. Sotheby's will auction the diamond, which is estimated to fetch $4.6 - $5.8 million, in Hong Kong on April 7. Photographer: Daniel Acker/Bloomberg via Getty Images
