In this undated photo provided by Christie’s Auction House in New York, a rare pink cushion-cut 9-carat diamond ring from the estate of the late copper heiress Huguette Clark is shown. The piece, believed to be owned by Clark’s mother, sold for $15,762,500 at Christies’ New York Magnificent Jewels auction on Tuesday, April 17, 2012. (AP Photo/Christie’s Auction House)