borosilicate colored glass tube Available colores :clear ,dark blue,light blue,amber,light yellow ,green ,pink,red and opaque b Material :artistic ... borosilicate glass Available colores :clear ,dark blue,light blue,amber,light yellow ,green ,pink,red and opaque black ,opaque white ... .2w/m2k7Refractive index0.921Main CompositionSiO2B2O3Na2O+K2OAl2O3811342 borosilicate colored glass tube 20120417