Minerals and Metals in Ancient India v2.c45.s5.6

v2.c45.s5.6

Alum has been known as *saurāṣṭra* (from Saurāṣṭra or Sūrat), as well as *kāmkṣī* and *tuvarī*. Ferrous sulphate was known as *kāsīsa* and copper sulphate as *sasyaka*. These alteration products originated from rocks and mines. Several nineteenth century literatures described their manufacture (in Cutch, Rajasthan, etc.) by successive operations of lixiviation, evaporation and crystallisation. (Ray, 1956: 230-33) Similar processes must have existed earlier for many centuries.