Identification of forgeries in historical enamels by combining the non-destructive scanning XRF imaging and alpha-PIXE portable techniques

The high concentration values of Pb in the glass matrix as well as the extensive use of chemical components based on Cr, Zn, and As, questioned the authenticity of the three artworks and postponed their manufacturing dating from the XVIII century AD. The application of a matrix factorization analysis to the XRF data allowed highlighting the chemical associations among Cd, Se, Ba and Zn, indicating the use of a modern cadmium lithopone in the red decorations. The analytical results obtained during the investigation suggest a classification of the three objects as modern copies.