Minerals and Metals in Ancient India v1.c11.s10.5

v1.c11.s10.5

The degraissants used were mica, sand and lime, alone or more rarely in combination. Marshall thinks that there seems to have been a natural admixture of sand in the alluvial clay used at Mohenjo-Daro. Mica is very common and betrays itself by its sparkle. This substance is very frequently found in the sand on the banks of the Indus and is readily extracted from it by levigation. It is especially useful as a tempering material in that when properly mixed with the clay, it greatly adds to the case of working the latter on the wheel; it also facilitates the drying of the pottery without cracking. Lime is commonly present in the fabric of both small and large jars which works as a tempering material confined only to Mohenjo-Daro material. The particular use served by lime as a degraissant still remains a matter of opinion, but with certain clays it appears to be an indispensable ingredient, and it has been mixed with them from the earliest time. (MCK, 176; MS-I, 289)