Patent ID: 8158543

Claim:
A silicate glass, the silicate glass having a seed concentration of less than about 1 seed/cm 3 , wherein the silicate glass comprises: 60-72 mol % SiO 2 ; 6-14 mol % Al 2 O 3 ; 0-15 mol % B 2 O 3 ; 0-1 mol % Li 2 O; 0-20 mol % Na 2 O; 0-10 mol % K 2 O; 0-8 mol % MgO; 0-10 mol % CaO; 0-5 mol % ZrO 2 ; 0-1 mol % SnO 2 ; 0-1 mol % CeO 2 ; less than 50 ppm As 2 O 3 ; and less than 50 ppm Sb 2 O 3 ; wherein 12 mol %≦Li 2 O+Na 2 O+K 2 O≦20 mol % and 0 mol %≦MgO+CaO≦10 mol %, wherein the silicate glass is formed from a batch or raw materials that includes at least one fining agent, wherein the fining agent comprises at least one inorganic compound and is substantially free of antimony and arsenic.