Fig. 10From: Glass ornaments from southwestern Taiwan: new light on maritime glass exchange across Southeast, South and West Asia in the early-mid 1st millennium CEBivariate plot of (a) CuO-SnO2 and (b) CuO-PbO showing the use of different copper-containing ingredients as colourants in the blue glass in the v-Na-Ca major and v-Na-Ca high Li sub-groups. (c) and (d): Lower concentration of the impurities related to the copper colourants can also be observed in the v-Na-Ca high Li sub-group than the v-Na-Ca major sub-groupBack to article page