Marbles in the façade of the "Certosa di Pavia": a physico-chemical study.

In the framework of an interdisciplinary research project on the well known monastery "Certosa di Pavia", the thermal and structural properties of marbles employed in the construction of the façade of the basilica were investigated in order to detect the main decomposition phenomena occurring on the monument surface. The results obtained by means of thermogravimetric and differential thermal analyses, as well as by means of X-ray diffraction and IR spectroscopy, allowed one to characterize samples taken from various sculptures of the façade and to bring out the degradation phenomena occurring in some of them, in particular the formation of "black crusts" with a high content in gypsum. The present findings are in fair agreement with those reported by other research groups which also studied with different techniques the construction materials of this monument.