Lesotho diamond put up for sale

The "Lesotho Promise", the largest diamond found this century, has gone on sale in the Belgian city of Antwerp.

The 603-carat gem is the 15th largest ever discovered. "It's about a third bigger than a golf ball," a spokeswoman for the owners said.

But the largest diamond ever recorded is the Cullinan, found in 1905 in South Africa, which weighted in at 3,106 carats.

The 503-carat Star of Africa was cut from it and now forms part of the British crown jewels displayed in the Tower of London.