A 603-carat diamond was sold for more than $12 million at an auction in Antwerp, Belgium.

The South African Diamond Corporation, which owns Graff jewelers, purchased the diamond.

It was named the "Lesotho Promise," after the African mountain kingdom where it was discovered.

It is the 10th largest white diamond ever found, and the largest found in 13 years.

The gem will be cut up and the pieces will be made into a large heart-shaped diamond and several smaller stones.

Johnny Kneller from the South African Diamond Corporation told Reuters that once the diamond is cut up, the stones are expected to make a significant amount of money.

He said, "We can't say for sure but we hope it's going to fetch over $20 million."

The diamond was found at the Letseng Diamond Mine by a woman who was sorting through the rocks.

"She started screaming and all the staff thought she had been electrocuted," said Clifford Elphick, head of Gem Diamond Mining.