Analytical characterization of paintings on pre-Roman pottery by means of spectroscopic techniques. Part II: Red, brown and black colored shards

As a part of a systematic study aimed at assessing the chemical composition of ancient pigments as well as at collecting information useful for the un derstanding of the technical aspects related to pottery preservation and de coration, the results of analysis performed on red, brown and black pigment s decorating pre-Roman pottery excavated in thirteen different tombs uneart hed in the archaeological zone of Canosa (Puglia, Italy) are presented. Bot h surface (XPS) and bulk (ET-IR) spectroscopies were used which gave comple mentary information and XRD was used in some cases to further support the s pectral assignments. Results suggested that the shards characterized by "no minally" the same color could be differentiated by the chemical composition of the pigmented layers; in particular, the shards exhibiting the red pigm ent could be divided into three groups containing, respectively, either hem atite or ochre plus other substances not related to the color but of great concern for the understanding of ancient techniques used for color preparat ion. Manganese oxides were found to be the basis of the brown pigments, whi ch could be divided into three groups on the basis of Mn and Fe contents. E ither magnetite or carbon of vegetable origin was found in the black-pigmen ted layers. Furthermore, an attempt was made to find a possible correlation between this classification and the results of a provenance study carried out on the same pool of shards analyzed in the present investigation.