One of the world’s largest diamonds has been sold for $40 million in an auction in the city of Antwerp, Belgium, the mining company Gem Diamonds Limited said Tuesday. The company said the 910 carat diamond, which is the fifth-largest gem-quality diamond ever found, bigger than a golf ball, was sold to an undisclosed bidder. The diamond was found in the Letseng mine in the small southern Africa nation of Lesotho, said Gem Diamonds Limited. According to the German News Agency, Lesotho is a small, impoverished country surrounded entirely by South Africa. Noteworthy, a rough diamond from Botswana, believed to be the biggest uncut diamond found in a century, was sold for $53 million in September.