#name   Format    SiO2  main component of most of Glass
glass	1
#
#  Elem	 rho(g/cm^3)	Gas/Solid(1/0)   refl.index Birks C

2         2.2		0          1.458     0 0 0
# 	Z	A  	N
	14	28.09	1
	8	16	2
