Africa-focused miner Petra Diamonds yesterday said its full-year revenue rose 24 per cent, as higher rough diamond prices and demand in Asia offset falling production. Revenues were $221m (£137m) in the year to the end of June and would have jumped 55 per cent including the $35m sale of the Cullinan Heritage diamond (pictured). The gem, included in the firm’s 2009-10 figures, set a record price for a rough diamond.