By Erika Winters
Petra Diamonds announced the recovery of a rare 25.5-carat rough blue diamond at the Cullinan mine in South Africa.
The high-quality diamond is considered top color and is among a number of blue diamonds--including a 26.6-carat rough stone that yielded a 7.0-carat fancy-vivid blue, internally-flawless polished diamond--since Petra acquired the mine. The 7.0-carat blue sold at Sotheby's in May 2009 for $9.49 million, which at the time was the highest price for a fancy-vivid blue diamond sold at auction. The rare gem was named the "Star of Josephine" by its new owner.
