A beautiful, rare blue diamond weighing 5.30 carats fetched more than five times its estimated price at auction on Wednesday, bringing in nearly $9.6 million and setting a new price-per-carat record.
"We are delighted with the price it has made," Jean Ghika, director of Bonhams Fine Jewelry, which held the sale in London, said in a statement. "It was a sensational stone which charmed everyone who viewed it prior to the sale."
The 5.30-carat diamond -- a little smaller than the diameter of a dime -- was made into a "Trombino" ring by famed Italian jewelry designer Bulgari in 1965. It's a cushion-shaped fancy deep-blue diamond, set horizontally and framed by brilliant-cut and baguette-cut white diamonds. (In gemstone terms, "fancy" means that the color is very intense.) The winning bid came from Graff Diamonds, an international jewelry house on Bond Street in London, Bonhams reported.
The gem gets its unique color from natural traces of the element boron mixing with the carbon atoms in the stone. Since boron conducts some electricity, blue diamonds look even more blue when they are warm. Less than one percent of all diamonds mined are blue.more