Patent ID: 6998362

Claim:
A neutral gray colored glass composition having a base glass portion comprising: SiO 2 65 to 80 percent by weight Na 2 O 10 to 20 percent by weight CaO 5 to 15 percent by weight MgO 0 to 10 percent by weight Al 2 O 3 0 to 5 percent by weight K 2 O 0 to 5 percent by weight and a colorant portion consisting essentially of: Fe 2 O 3 (total iron) 0.30 to 0.70 percent by weight FeO 0.08 to 0.16 percent by weight Co 3 O 4 3 to 25 PPM Se 0.5 to 10 PPM wherein the color of the glass is characterized by a dominant wavelength less than 560 nanometers, a color purity of no higher than 6 percent and a visible light transmission of 70 percent or greater at a thickness of 4 millimeters, and wherein the percent reduction of the total iron is between 21% and 34%.