Minerals and Metals in Ancient India v1.c26.s6.t3.2

v1.c26.s6.t3.2

X-ray diffraction and polarised light microscopy of polished thin sections (Freestone *et al.*, 1985a: 236) show the pellets to be composed primarily of carbonates (of Ca and Mg) but their state of aggregation and rigidity is imparted by a skeleton of silicate glass, in which are embedded numerous crystals of diopside. Fine grains of metallic iron were also seen. The EPMA or Electron-Probe Micro-analysis data (columns 1 and 2 in Table 18.2) show association of diopside CaMgSi₂O₆ crystal with some Fe, Mn and Zn. The glass is rich in zinc, containing up to fifteen weight per cent ZnO, and also contains higher proportions of Al, Mn, Na, K, Cl and P₂O₅.