X-Ray portable spectrometry and ICP-AES: comparison between non-destructive and destructive techniques for the chemical characterisation of mosaic glasses

Among non destructive techniques for the determination of the chemical composition of glasses X-Ray Fluorescence portable spectrometry avoid any sample manipulation and has the great advantage of in situ measurements. In addition, in order to verify the heterogeneous chemical composition and to identify different sampling points, such technique allows an extensive investigation of the single tesserae and of wider areas of the mosaics. To compare performances and limits of destructive and non destructive techniques, ICP-AES analysis and portable X-Ray Fluorescence spectrometry have been performed on glass standards and on a selection of mosaic tesserae. This is a laboratory test to be developed into an in situ analytical protocol at use and advantage of art historians and conservators for their “first-sight” knowledge of the mosaic glass characteristics.