US Patent 7691763 High performance blue glass

A glass composition for forming a blue colored glass is disclosed. The glass composition is made up of a base glass portion, iron oxide, and at least one first additive compound selected from Nd2O3 in an amount up to 1 weight percent and/or CuO in an amount up to 0.5 weight percent. The base glass portion has the following components: SiO2 from 66 to 75 weight percent; Na2O from 10 to 20 weight percent; CaO from 5 to 15 weight percent; MgO from 0 to 5 weight percent; Al2O3 from 0 to 5 weight percent; B2O3 from 0 to 5 weight percent; and K2O from 0 to 5 weight percent. The total iron in the glass composition ranges from 0.3 to 1.2 weight percent, and the glass composition has a redox ratio ranging from 0.15 to 0.65.