Minerals and Metals in Ancient India v1.c28.s8.t5.28

v1.c28.s8.t5.28

Theophilus knew in the twelfth century that gilding is better done on unalloyed copper rather than on brass or leaded brass. (Oddy et al., 1981: 92) The presence of lead and zinc on the surface causes ‘white spots resistant to even drying’, there being no such problem on copper surface. The Indian and Nepalese artistes must have known this phenomenon through practical experience. This is confirmed by Schroeder’s (1981) observation that of the ten Pāla period images, the eight ungilded ones were made of brass, bronze or leaded copper while the two gilded ones were cast of almost pure copper. Analysing pre-seventeenth century Himalayan images, Oddy *et al.* (1981: 94) observed that the fire-gilded icons mostly contain less than 5 per cent zinc, while there is a large group of ungilded objects with higher zinc content (12 to 32 per cent).