The 9.51-carat “Mellon Blue” diamond sold for $25.5 million at Christie’s Geneva Magnificent Jewels auction, held Tuesday at the Four Seasons Hotel des Bergues. The fancy vivid blue pear-shaped ...
A 9.51-carat blue stone that once belonged to the heiress Bunny Mellon sold for $7 million less than at its last auction, a sign of profound shifts in the diamond industry. By Ashley Ahn A 9.51-carat ...