Minerals and Metals in Ancient India v1.c21.s1.3

v1.c21.s1.3

Since the Harappan era, the etched varieties, the beads having decorative patterns etched on their surfaces by some chemical process, were known in India. (Dikshit, 1949) According to the method of their manufacture, three principal types of etched beads have been recognized. These are white patterns on red background (Type I), black patterns on whitened surface of stone (Type II) and black patterns etched directly on the stone (Type III). In type I, the thick liquid applied on red carnelian contained potash, white lead and the juice of the Kirar bush. In Type II, the surface was whitened by alkali treatment and patterns in black lines were drawn using mineral salts of copper and manganese. In Type III the salt liquor was used directly on the surface. It is quite likely that Chanhu-Daro, during the Harappan era, and Cambay, during the Historical Period, were the active centres for the production of the etched beads.