Advantages and disadvantages of PIXE/PIGE, XRF and EDX spectrometries applied to archaeometric characterisation of glasses

The analytical advantages and disadvantages of PIXE/PIGE spectrometry have been checked and compared with those of other X-ray techniques (XRF and EDX) for a wide set of glasses. The archaeometric study was conducted with glasses of different chronology (13th to 20th centuries AD) and different Spanish provenances. Glasses produced in Central Europe during the medieval period were submitted to severe corrosion processes, which induced conservation problems. Since this subject is directly connected with their chemical composition, a glass whose composition is considered as a representative model was melted at the laboratory and included in the samples set. In general, the results of chemical analyses undertaken with different techniques indicate that percentages for the main vitrifying agents and modifying agents are in good agreement. PIXE/PIGE spectrometry arises as a useful non-destructive analytical tool able to determine at the same time heavy and light oxides, as well as minor components (colouring agents). PIXE/PIGE spectrometry has also demonstrated its usefulness to characterise on the glass surface features concerning decorations (grisailles), glassy coloured layers, corrosion crusts and other products of weathering and aging.