JOHANNESBURG (AFP) – Mining group Petra Diamonds has discovered a 507.55 carat white diamond at South Africa's Cullinan mine, one of the largest high-quality rough diamonds ever found, the firm said on Tuesday.
"This spectacular gemstone was recovered on Thursday 24 September and is currently with experts for analysis," said a statement released by the London-listed company which operates mainly in Africa.
Initial examinations of the diamond which weighs just over 100 grams (3.5 ounces), have shown it to be of exceptional colour and clarity.
The precious stone was found alongside three other special white gems of similar colour and clarity, a large diamond of 168.00 carats and two other stones of 58.50 and 53.30 carats.
In May 2008, the mine produced a sparkling 101.27 carat diamond, roughly the size of a ping-pong ball.
The Cullinan Diamond Mine is the third richest diamond producing mine in South Africa.