Patent ID: 7825051

Claim:
A glass composition comprising a base glass composition comprising: SiO 2 65 to 75 weight percent, Na 2 O 10 to 20 weight percent, CaO 5 to 15 weight percent, MgO 0 to 5 weight percent, Al 2 O 3 0 to 5 weight percent, K 2 O 0 to 5 weight percent, and BaO 0 to 1 weight percent, and a colorant and property modifying portion comprising: total iron up to 0.02 weight percent, CeO 2 0.05 to 1.5 weight percent, CoO 0 to 50 PPM, Se 0 to 15 PPM, Cr 2 O 3 0 to 500 PPM, CuO 0 to 0.5 weight percent, V 2 O 5 0 to 0.3 weight percent, TiO 2 0 to 1 weight percent, NiO 0 to 200 PPM, Er 2 O 3 0 to 3 weight percent, MnO 2 0 to 0.6 weight percent, and Nd 2 O 3 0 to 2 weight percent, wherein the glass composition has a redox ratio up to 0.55, and the colorant and property modifying portion further comprising Er 2 O 3 in a range of 0.5 to 2 weight percent or Nd 2 O 3 in a range of 0.5 to 2 weight percent.