Minerals and Metals in Ancient India v2.c43.s3.t7.27

v2.c43.s3.t7.27

Having discussed the group of minerals representing unhydrated crystalline silica, named quartz, rock-crystal and *sphaṭika* (in Sanskrit), we may proceed to discuss the other group, namely chalcedony, which is SiO₂, nH₂O hydrated silica, having lower hardness (6-1/2) and appearing in many forms and colours. Before we do that, we propose to record the observations on *bhīṣma* in the Sanskrit literature; we are not certain whether *bhīṣma* belongs to the quartz or the chalcedony sub-family. Tagore (1879: 497-501) has equated *bhīṣma* with rock-crystal, whereas Sarma (1984: 70) thinks that ‘it is probably some kind of white chalcedony’.