Optical glasses, stable to devitrification, of high RI, low colour content and capable of being fused have compositions (wt%): 15-20 SiO2, 8-10 B2O3, 27-37 BaO, 0-3 CaO + SrO, 15-24 La2O3, 3.5-5.5 ZrO2, 6-13 TiO2, 5-7 Ta2O5 or Nb2O5, provided that ZrO2 + TiO2 + Ta2O5 or Nb2O5 does not exceed 23, As2O3 0.5-1.5, and CdO and/or PbO and/or Bi2O3 and/or WO2 0.5-4.5.
Origin
Unknown
Journal Title
Bp 1 089 597, 1/11/67
Sector
Refractive Indexes
Class
RI 39