Patent ID: 6962887

Claim:
A method of making clear glass having an azure edge coloration and low amber surface coloration in a non-vacuum float glass system, comprising: providing a non-vacuum float glass system having a melter and a molten metal bath; and melting batch materials to provide a final glass product comprising: SiO 2 65-75 wt. %; Na 2 O 10-20 wt. %; CaO 5-15 wt .%; MgO 0-5 wt. %; Al 2 O 3 0-5 wt. %; K 2 O 0-5 wt. %; and a colorant portion comprising: total iron (Fe 2 O 3 ) 0-0.02 wt. %; CoO 0-5 ppm; Nd 2 O 3 0-0.1 wt. %; and CuO 0-0.03 wt. %, wherein the glass has a redox ratio in the range of 0.3 to 0.6, wherein the glass has a retained sulfur content of less than or equal to 0.11 wt. % SO 3 , and wherein the batch materials comprise sodium sulfate and sodium nitrate, with the sodium sulfate present in an amount to provide a final glass product having less than or equal to 0.11 wt. % SO 3 .