Patent ID: 7538053

Claim:
A glass composition comprising, in weight percent: SiO 2 64-75% Al 2 O 3 0-5% B 2 O 3 0-5% CaO 5-15% MgO 0-5% Na 2 O 10-18% K 2 O 0-5% and coloring agents which comprises, in weight percent: Fe 2 O 3 (total iron) 0.2-0.45% Se 2-8 ppm CoO 0-20 ppm NiO 0-80 ppm wherein said coloring agents satisfy the following relationship: 0.7<(200×NiO)+(5000×Se)+(6×Fe 3+ )/(875×CoO)+(24×Fe 2+ )<1.6 wherein the NiO, Se, Fe 3+ , CoO and Fe 2+ contents are expressed in ppm, Fe 3+ is the content of ferric iron expressed in the form of Fe 2 O 3 and Fe 2+ is the content of ferrous iron expressed in the form of FeO, wherein the composition has an excitation purity of less than or equal to 2%, a redox from 0.28 to 0.5, an overall light transmission under illuminant A (T LA ) greater than 65% and a selectivity (SE) of greater than 1.25, when measured for a thickness of 3.85 mm.