An Encyclopaedia of Indian Archaeology v1.c21.s8.7

v1.c21.s8.7

KOPIA, three specimens, all early historical: KP1 is a colourless bead: KP2 black bead; KP3 pale yellow strip. KP1 is colourless due to the low proportion of ferric iron (2·50%) and the presence of manganese (0·1 manganese oxide). The black colour of KP2 is due to the high iron content and the pale yellow colour of KP3 of the low proportion of iron and a low concentration (0·08%) of manganese, which was evidently not sufficient to decolourize the glass completely. All the specimens are characterized by a low content of lime and magnesia and a high content of iron oxide and alumina. The specific gravity ranges from 2·51 to 2·53.