Cobalt Glass Games Stone 2

                                    Cobalt Glass Games Stone    COBALT GLASS
By Aamir Mannan.

The position of cobalt  bands in glass varies a little with the composition of the glass concerned. Average measurements are 6550, 5900 and 5350 A. The 


distinction between this blue and synthetic blue spinel by means of the spectroscope is easily made, according to the relative width of the 


central band , as mentioned above. Cobalt glass is often used as the base of blue garnet- topped doublets the supervision of a faint almandine spectrum on that of the cobalt glass may give a rather confusing effect unless the nature of the stone is apprehended.