London-listed miner Vast Resources is to be allowed into Zimbabwe’s diamond fields, Mining Minister Winston Chitando said on Thursday, joining other new entrants including Russia’s Alrosa. Zimbabwe is stepping up efforts to exploit its mineral resources to revive a moribund economy sapped by high inflation and unemployment, with President Emmerson Mnangagwa looking to woo investors after a soft coup in 2017 that usurped former president Robert Mugabe.