Last Updated: Nov 22, 2016 Views: 28
From Dr. Robert Brill, Research Scientist Emeritus:
My guess is that it would be either the pigment lead-antimonate (sometimes known when used in Western paintings as "Naples yellow") or a similar compound, lead-tin oxide. The chemical formulas are: Pb2Sb2O7 and PbSnO3. Those were the two most common yellow colorant opacifiers used for some 3300–3400 years of glass history.