In order to get realistic glass objects I suggest you to make a completely
transparent pigment (i.e. rgbf 1 or rgbf .98...)
and to add absorption media to get the colour of the glass (i.e. absorption
3*(1-your_colour)). With a bit of turbulence (in a density statement) I
always got excellent results and the glass objects should lose that
physically unrealistic glowing effect.
JRG.
