petra diamonds ltd said tuesday that its net profit fell in the first half of the fiscal year as a result of negative currency movements the mining company which produces diamonds in south africa and tanzania made a net profit of 491 million in the six months ended dec 31 this was down from 676 million a year earlier reflecting a 634 million noncash impact from foreign exchange movements however adjusted pretax profit jumped to 911 million from 65 million reflecting improved diamond prices the recovery of exceptional stones and cost reductions our strengthened operating platform and balance sheet coupled with the robust rough diamond market sets us well for the second half of the year and we are well on track to meet fy 2022 operational guidance chief executive richard duffy said petra expects to produce between 33 million and 36 million diamond carats in fiscal 2022