Petra recovers 20 ct blue diamond at Cullinan

London-listed Petra Diamonds has recovered a 20.08 ct blue gem-quality Type IIb diamond from the Cullinan mine, in South Africa's Gauteng province.

"Today's recovery not only demonstrates the quality of Petra's asset base, as the Cullinan diamond mine remains a significant source of rare blue diamonds, but it again confirms the prevalence of exceptional stones in the Cullinan orebody, as well as the ability of the mine's plant to recover the full spectrum of diamonds," the company noted in a press release on Monday.