(IDEX Online) - Rio Tinto reported a small drop in first quarter diamond production at its Diavik mine in Northwest Territories, Canada. It recovered 954,000 carats, down four per cent from 991,000 carats in Q1 2022, and down 27 per cent on Q4 2022.Rio Tinto, the world's second-largest metals and mining corporation, said the lower production was because of temporary restrictions accessing open pit material.In February it announced a $40m plan to invest in underground mining and prolong Diavik's life to early 2026.Production for the full year of 2022 was 4.65m carats. In January the miner revised down its 2023 forecast to 3.0m to 3.8m carats.The deposit, 300 km northeast of Yellowknife, is one of the largest employers in Northwestern Territories, providing 1,100 jobs, and contributing almost 10 per cent of its GDP.Rio Tinto has been 100 per cent owner of the mine since November 2021, ending a long legal battle with Dominion Diamond Mines over operating costs and production targets.Dominion went into administration in April 2020 and Rio Tinto bought its 40 per cent holding.Pic shows Diavik mine, courtesy Rio Tinto