Minerals and Metals in Ancient India v2.c45.s4.7

v2.c45.s4.7

*Tuvarī* or alum used to be obtained from the mountain rocks of Saurāṣṭra. This was widely used as a mordant to bind and deepen the colour of a dye such as mañjiṣṭha (RRS, 3.59). Two varieties were recognised: slightly yellow, heavy and brilliant phaṭakī or piṭikā, and white, light and amla or sour in taste, phullikā. The latter was known to react with copper sheets (RRS, 3.61-62) indicating the reactivity of copper with the sulphate ion from alum. Kāṅkṣī described as kaṣāya or astringent is also alum.