Analysis of polychrome Iron Age glass vessels from Mediterranean I, II and III Groups by LA-ICP-MS

In this work the analytical results obtained by ICP-MS with laser ablation solid sampling and SEM-EDS for some polychrome glass vessels from the Iron Age are presented and discussed. The samples, coming from Etruscan sites near Adria (Northern Italy), belong to the so-called Mediterranean Groups I, II and III and are dated from the 5th, 3rd and 2nd century B.C., respectively. To date, analytical data for only two sets of vessels of the same age have been discussed in the literature. In spite of the low number of available samples, this is the first time that vessels of all three periods are analytically compared. Elemental concentration data show that the samples can be classified as low-magnesia-low potash (LMLK) soda-lime-silica glasses, with low phosphorus and titanium contents, in agreement with data for similar samples of the same age. Bivariate and multivariate analyses of the contents of many elements characterizing the siliceous sands showed three distinct sets corresponding to the three periods. Since the sets indicate different provenances of the sands it seems rational to assume that different glassmaking locations were involved. Chromophores and opacifiers of blue bodies and yellow, white and turquoise decorations of the vessels were analytically identified, while the nature of the corresponding ores was hypothesized.