Non-destructive Approach to Multilayer Objects: XRF Analysis of Gilt and Enamelled Metals of the Medieval Cross of Rosciolo

The penetration of X-rays is usually a limitation to the application of XRF analysis to multilayered materials, however it is possible, by software tools based on the fundamental parameters method, to overcome this problem and estimate thickness and composition of each layer. The cross of Rosciolo is a significant example of multilayer object: it is made of a wood core with attached gilt silver sheets and decorated with enamels. Measurements were carried out in situ and the PyMCA software was employed. The values of gilding thickness, Au/Hg ratios and Cu content in the silver sheets, and enamel's composition are discussed.