Minerals and Metals in Ancient India v1.c26.s6.t3.18

v1.c26.s6.t3.18

In addition to zinc smelting, Zawar yielded considerable evidence for the smelting of lead, in the form of at least sixteen deposits of slag, distributed along the valley of the river Tiri. We have mentioned these slags in our previous chapter and provided their compositions in Table 17.5. The glassy slag, not associated with zinc-smelting debris, assayed high in zinc content (7-11%) and contained melilite Ca₂ZnSi₂O₇, apart from olivine Mg₂SiO₄ and magnesium-rich clinopyroxene CaMgSi₂O₆. The crystalline slag was associated with zinc retort distillation debris, and contained lower proportions of zinc (less than 3%) presumably because this metal had been extracted or lead smelting was done after manual separation between sphalerite-rich and galena-rich portions of the rock.