Use of Raman microspectroscopy to characterize wallpaintings in Cerro de las Cabezas and the Roman villa of Priego de Cordoba (Spain)

The analysis by Raman microscopy of several wallpainting fragments found at an archaeological site in Fuente Tojar and in the Roman villa of Priego de Cordoba, both in southern Spain, revealed that the most abundant colours in them were obtained from the usual pigments of the time. Thus, red corresponded to red ochre, which consisted of hematite mainly. Also, yellow came from yellow ochre (goethite), blue from Egyptian blue, and grey hues were obtained from mixtures of coal and calcite occasionally also containing gypsum. The components of some pigments were confirmed by X-ray diffraction spectroscopy. The two spectroscopic techniques were additionally used to examine the mortars and the preparatory layer present in the fragments.