LSE-listed Petra Diamonds has recovered a 138.57 ct Type IIa, D-colour diamond at its Cullinan mine, in South Africa. The high-clarity diamond will be offered for sale as part of the company’s next sales process later this month. The company had earlier this year sold a 121.26 ct white diamond recovered from the same mine to a joint venture between Dubai-based diamond trading company Nemesis International and Golden Yellow Diamonds for $6-million.