In search of Etruscan colours: A spectroscopic study of a painted terracotta slab from Ceri

Painted terracotta slabs, which are characteristic of Etruscan art, are much less known than the funerary frescoes of the Etruscan necropolis, and have never been studied by advanced diagnostic techniques. To get information on the manufacturing methodology of these important works of art, detailed micro-Raman and X-ray diffraction measurements were performed on a polychrome terracotta slab representing a warrior, found in the ancient Etruscan town of Ceri. We have found that the terracotta slab, which was made using a calcium-poor clay, was fired at a temperature in excess of 800 degrees C. For the polychrome, we have identified red ochre, azurite, yellow ochre, burnt umber and carbon black pigments, and we propose the use of kaolin as a white pigment, thus providing a reliable, although not definitive, description of the colour palette. On the basis of the obtained results, which do not reveal the presence of organic binders, we propose that a second firing procedure was carried out on the work of art at between 250 degrees C and 300 degrees C, in order to fix the pigmented layers.