On roasting arsenopyrite in air, arsenic sublimes as arsenic(III) oxide leaving iron oxides, while roasting without air results in the production of gray arsenic. Further purification from sulfur and other chalcogens is achieved by sublimation in vacuum, in a hydrogen atmosphere, or by distillation from molten lead-arsenic mixture.
on roasting arsenopyRiTE IN air, aRsenic sUblImeS as arSenic(iii) oxide lEaViNg irOn Oxides, while rOasting wiThout air rEsuLts in thE ProDUction Of Gray arsenIc. furthEr pUrIFIcatiOn froM sulFuR AnD OThEr chAlcogEnS iS acHieved by suBlimation in VaCuuM, In a HydRogen atmosPHere, or bY distilLation fRom molTen lead-arsEnic mixtuRE.