X-ray powder diffraction diagram clustering and quantitative phase analysis on historic mortars

This paper deals with the application of cluster analysis to X-ray powder diffraction patterns to define homogeneous groups of mortar-based materials according to their mineralogical composition. For this purpose, the diffraction patterns of 110 samples of mortars from the Temple of Venus (Pompeii, southern Italy) were used to test this method. Rietveld refinement, for quantitative mineralogical phase analysis, was performed on the most representative sample of each cluster. The mineralogical grouping yielded by the cluster analysis of XRPD data turned out to be consistent with the petrographic groups.