$20M Diamond Found
Egg-sized diamond ranks among the highest quality gems ever discovered
By Rob Quinn,  Newser Staff
Posted Sep 30, 2009 1:42 AM CDT
Petra Diamonds CEO Johan Dippenaar holds the 507.55 carat white diamond recovered at the Cullinan Diamond Mine in South Africa.   (AP Photo/Petra Diamonds)

(Newser) – A giant diamond experts believe ranks among the top 20 gems ever found has been unearthed at a South African mine. The egg-sized, 500-carat sparkler was found at the same mine where the biggest diamond in history, the Cullinan, was found in the 19th century. The diamond is being analyzed and is expected to be worth over $20 million when it's cut and polished.