SECTION XIII - ARTICLES OF STONE, PLASTER, CEMENT, ASBESTOS, MICA OR SIMILAR MATERIALS; CERAMIC PRODUCTS; GLASS AND GLASSWARE > CHAPTER 70 - GLASS AND GLASSWARE > 7004 Drawn glass and blown glass, in sheets, whether or not having an absorbent, reflecting or non-reflecting layer, but not otherwise worked > Glass, coloured throughout the mass (body tinted), opacified, flashed or having an absorbent, reflecting or non-reflecting layer > Optical glass