Pigments used in Roman wall paintings in the Vesuvian area

Powdered pigments found in bowls from the Pompeii archaeological site and some wall-painting fragments from the Vesuvianarea (conserved in the National Archaeological Museum of Naples) were investigated by microscopic Raman and FTIRspectroscopies, X-ray diffraction and scanning electron microscopy-energy dispersive X-ray. Brown, red and yellow pigmentsare common ochres based on goethite and haematite. The blue pigment is Egyptian blue: the presence of tridymite and cristobalite indicates firing temperatures in the 1000.1100 .C range. Pink pigments were prepared both with purely inorganicmaterials, by mixing haematite and Egyptian blue (violet hue), or presumably by adding an organic dye to an aluminium-silica matrix. Awhite powder found in a bowl is composedmainly of the unusual pigment huntite (CaMg3(CO3)4). Celadonite is found in the green samples from the wall paintings, together with Egyptian blue and basic lead carbonate, while the heterogeneous green pigment in a bowl shows malachite mixed with goethite, Egyptian blue, haematite, carbon, cerussite and quartz