Composition of the base glass used to realize the stained glass windows by Duccio di Buoninsegna (Siena Cathedral, 1288–1289 AD): A geochemical approach
Elena Basso|María Pia Riccardi|Bruno Messiga|M. Mendera|D. Gimeno|Maite Garcı́a-Vallés|J. L. Fernández-Turiel|Flavia Bazzocchi|M. Aulinas|Camillo Tarozzi
A set of 35 samples from the rose window Siena Cathedral (Tuscany, Italy) has been studied using EMPA to define chemical composition (17 major and minor elements) base glass. This paper focuses on colourless natural-coloured glasses, i.e. glass produced without intentional addition colouring agents. The presence natural impurities Fe Mn, as well control furnace conditions plays an important role well. Three compositional groups have identified taking into account Al/Ti ratio K2O MgO concentrations. most represented homogeneous group contains original glasses defines composition. It is a soda–lime based quartz (pure sand or quartz-bearing pebbles/rocks) vitrifying component Na-rich plant ash flux. Restoration interventions explain other two groups. comparison with coeval Tuscany (Italy) allowed us postulate local production for them.
Materials Characterization