Integration of both non-invasive and micro-invasive techniques for the archaeometric study of the glass stained windows Apparizione degli Angeli from Santa Croce Basilica in Florence

The basilica di Santa Croce (basilica of the Holy Cross) is the main Franciscan church in Florence (Italy)and the largest in the world. In the church there are 22 stained-glass windows. In 2000, the Opera di SantaCroce began a restoration campaign of the fourteenth-century windows. This paper reports the archaeo-metric data collected from the stained-glass window Apparizione degli Angeli (Apparition of the Angels).For the first time the integration of both non-invasive and micro-invasive techniques was adopted inorder to limit the number of samples and, at the same time, to have a good certainty of their representativeness. The results allowed identification of the presence of different major base glass compositions(potash-lime-silica and soda-lime-silica) and the coloring techniques. Results were also compared withdata obtained in past archaeometric studies on coeval stained-glass windows in Santa Croce.