Patent ID: 7507681

Claim:
A glass-ceramic material comprising bismuth as a coloring species in the visible range, wherein the glass-ceramic material has a composition, expressed in terms of percentage by weight of the total composition on the basis of oxides, consisting essentially of: SiO 2 : 60-70%, Al 2 O 3 : 17-22%, Li 2 O: 2-5%, MgO: 0-3%, BaO: 0-2%, CaO: 0-2%, SrO: 0-2%, ZnO: 0-4%, TiO 2 : 0-5%, ZrO 2 : 0-5%, TiO 2 +ZrO 2 : 2.5-6%, SnO 2 : 0-3%, Bi 2 O 3 : 0.1-10%, and CeO 2 +WO 3 +Nb 2 O 5 +MoO 3 : 0-1%.