Alteration phenomena on surfaces of stained glasses by Masters from XIII to XV centuries
Algarra Cruz E.L., Barbier N., Bruni S., Maino G., Marghella G., Volpe L.
Poster Conferenza Internazionale con referaggio
Stained glasses are physical and chemical complex systems, exposed to an aggressive environment because of their function. They can be described as an amorphous, porous solid state, resulting from sand fusion, with inclusion of fluxes (Na, K, Ca) as stabilizers and traces elements (Mn, Fe, Mg), responsible for their incredible colors. At our days, many studies were conducted for understanding alteration phenomena in medieval stained glasses, and developing new strategies for conservation and restoration. This complex issue remains an actual matter of research, as factors involved in alteration process are numerous and highly dependent on stained glasses chemical composition. Also an increasing interest was shown for identifying fabrication recipes and more precisely color recipes for stained glasses coming from different part of Mediterranean basin. The main point of the study is a comparative approach including both structural and chemical characterization for identifying alteration phenomena at the stained glasses/atmosphere interface and connect them with collected information on sample specificities. Samples were taken from the rose window designed by Duccio di Buoninsegna, during restoration campaigns of the Siena Cathedral. Other samples were taken on the stained glasses designed by Cabrini masters located in the Saint Petronio Basilica in Bologna. Surface analysis were performed using SEM/EDX in ENEA-UTSISM laboratory (Bologna) and coupled with a large range of other techniques including X-Ray fluorescence, X-ray diffraction and Ion Beam Analysis on AGLAE accelerator (C2RMF, Paris), in order to obtain a complete identification of structural and chemical modifications due to alteration at stained glasses surface.
Algarra Cruz E.L., Barbier N., Bruni S., Maino G., Marghella G., Volpe L. "Alteration phenomena on surfaces of stained glasses by Masters from XIII to XV centuries" InterM 2013 - International multidisciplinary microscopy congress