(IDEX Online) - The Murowa mine, in Zimbabwe, reported a 15 per cent drop in its diamond production for 2020 as known deposits begin to run dry.Owners RioZim said it was exploring sites near the three kimberlites pipes currently being worked in the southern central Midlands Province.Rough output in the year ending 31 December 2020 from the RioZim associate RZM Murowa Private Limited was 579,000 carats, down from 685,000 carats the previous year.RioZim chairman Saleem Rashid Beebeejaun said the main reason for the drop in yields was that the mine had been processing low-grade resources from its K2 pipe. High-grade resources at K1 have become depleted.But firm gold prices helped the minerals and mining parent company RioZim bounce back with a $454m profit in 2020, after a $584m loss in 2020.Pic shows the Murowa mine