A big blue diamond has been found at a South African mine known for churning out famous diamonds, and the stone could be worth tens of millions of dollars. The diamond, extracted from the Cullinan ...

"Everyone who has viewed the 20-carat polished diamond has marveled at its unique coloration, which many see as unlike any blue stone they have seen before. It is incredibly unusual for a stone of ...

"It is truly a once-in-a-generation stone, and quite simply the greatest blue diamond of its size I have ever seen," Patti Wong, chairman of Sotheby's Asia, said in a statement.