Minerals and Metals in Ancient India v1.c15.s4.8

v1.c15.s4.8

Iron content in the Ahar axe was high: 6.48 per cent, but in the copper sheet we find much lower value viz., 1.22 per cent iron, which means that removal of iron from copper was substantial. Considering that chalcopyrite ore of Khetri contains as high as 4 per cent arsenic and Ahar artefacts contain only traces, it is possible that the crushed ore might have been heated to a high temperature such as 500°C to remove arsenic. Lothal copper artefacts also contain negligible quantity of arsenic and for this we do not have to agree with S.R. Rao (1979 and 1985) that the ingot was imported from Oman. Lothal artisans might have learnt like the Aharians the technology of removal of arsenic from copper ore.