Gem Diamonds has sold the Letšeng Star, a 550 carat white diamond, for $16.5 million (R130.6m).
The gem is more than 1 000 times bigger than the average 0.5 carat engagement ring.
The Letšeng Star is ranked the 14th largest white diamond on record and is the fourth diamond of such historical significance to be recovered at the Letšeng mine in Lesotho since the company bought the mine in 2006. The $16.5m price tag is only an initial payment.
The listed diamond company will participate in the upside from profits when the polished stones are sold.
Gem Diamonds chief executive Clifford Elphick said the sale would improve the performance of the group.
“The Letšeng Star has the potential to yield an exceptional polished product. We are becoming increasingly successful in selling rough and polished diamonds with good margins being realised,” he said.
With the Letšeng Star, the mine has produced four of the 20 largest diamonds. The 603 carat Lesotho Promise sold for $12.4m in 2006, the 493 carat Letšeng Legacy went for $10.4m in 2007, and the 478 carat Light of Letšeng fetched $18.4m in 2008.