Diamond miner Petra Diamonds has tabled a production guidance for the 2018 financial year of between 4.8-million and five-million carats, up 23% on the year ended June 30, 2017, on the back of the continued roll-out of expansion programmes. With continual increases in production, the company set a further guidance of between five-million and 5.3-million carats for the 2019 financial year.