b) 0.25 to 15% by weight, based on total solids in the composition, of {HEAD ~ a lead tellurium lithium oxide} wherein {TAIL ~ the lead} tellurium lithium oxide comprises 0.1 to 5 wt % Li2O; and 
b ) 0.25 to 15 % by weight , based on total solids in the composition , of { HEAD ~ a lead tellurium lithium oxide } wherein { TAIL ~ the lead } tellurium lithium oxide comprises 0.1 to 5 wt % Li2O ; and
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH