Pigments and plaster from Thamusida (Rabat, Morocco)

A total of 22 samples were taken both from plasters still in situ and from collapsed material recovered by French, Italian and Moroccan teams at the Roman settlement of Thamusida (Rabat, Morocco). The sample characterization was obtained using optical microscopy, scanning electron microscopy, image analysis and Raman micro-spectroscopy. Plaster aggregate was made using a mixture of sands and clays that outcrop nearby, while lime was probably produced using the local limestone crust, as was further verified for the mortars. The plasters from the bath complexes (public buildings) and the Temple à trois cellae (sacred building) were very poorly made, while those from areas VII and XX (private buildings) indicated the involvement of more expert masons. The pigments used were cinnabar, red ochre, yellow ochre, Egyptian blue, green earth, chalk white and carbon black. The overall manufacture was of low quality, and hence perfectly comparable to that observed in other Roman Provinces. With respect to Italy and to other Mediterranean Roman sites, Thamusida fits well within an aesthetic and technical koinè that differentiates sites of the Italian peninsula from those in the Provinces.