I vetri dallo scavo presso il battistero del Duomo di Padova: studio archeometrico preliminare sui bicchieri gambassini

The present paper reports preliminary results of the archaeometric study, still in progress, carried out on the Late Medieval/Renaissance beaker defined “gambassino”, in order to identify the raw materials employed in its production, analogies and/or differences with Medieval/Renaissance glass from the Mediterranean area, and possible relationships between chemical composition and type and/or production technique, and to extend our understanding on this glass typology, of which few examples have previously been analysed. Six “gambassino” beakers excavated at the Baptistery of the Cathedral of Padua, all colourless and dated between the 2nd half of the 15th and the beginning of the 16th century, were selected for archaeometric analyses. This was carried out by means of electron probe microanalysis to identify bulk chemical compositions and multivariate statistic treatment of chemical data to identify analogies or difference with Medieval/Renaissance glass from Venice, the most important glassmaking center of the considered period. The samples are all soda–lime–silica in composition, with soda ash as flux and manganese as decolouriser, in accordance with the production technology of this period. Comparisons with the three Venetian Medieval/Renaissance compositional groups (common glass, vitrum blanchum and cristallo) suggest compositional analogies with vitrum blanchum, although some differences identified both in Padua samples and between samples from Padua and Venice are examined.