Minerals and Metals in Ancient India v1.c22.s6.8

v1.c22.s6.8

Other samples show the presence of sulphur indicating that sulphide ore of copper was the source. High purity of copper (97-98%) in these cases, showing 0.5 per cent sulphur suggest a high technological efficiency in copper metallurgy. 0.99, 1.13 and 1.23 percentages of antimony in copper samples No. 3, 13 and 14 respectively are too low to be considered as the results of deliberate alloying; on the other hand such appreciable values indicate that the antimony-rich copper ore from Badakshan, Balkh and Kabul might have been tapped to make the stated alloy. Such an ore might have been also used to make the earlier stated Taxilian white opaque glass (5.08% Sb₂O₃) and turquoise blue powder (2.42 Sb₂O₃ and 3.6 CuO). During the medieval period, antimony sulphide of this region was indeed used to make khārsini alloy and cast into ‘hairclips and amulets for the women of Hindustan’ (Al-Bīrūnī), and antimony mirrors. This trend might have started with the first century AD Taxilian mirrors (see No. 14). The sample No. 8 contains a high percentage of lead which was added probably to facilitate casting. Unalloyed copper was never cast at Taxila.