An integrated spectroscopic approach to investigate pigments and engobes on pre-Roman pottery

Painted Canosa ceramics were examined to identify the nature of the pigments employed and their manufacturing technology. A multi-technique approach was used, comprising Raman microspectroscopy and laser ablation hyphenated to inductively coupled plasma-mass spectrometry (LA-ICP-MS). The analysed samples were mainly produced for burial in tombs and were not intended for everyday use. They belong to the period between the end of the mid-7th century and the first half of the 4th century BC, and were excavated from the Toppicelli archaeological district near the suburbs of Canosa (Puglia, Italy). Forty-eight pottery fragments were available for this study. No handling of the samples was required for the Raman study, and it was possible to excise the pigmented layer in such a way that the lacunae were not distinguishable to the naked eye due to the micrometric size of the laser spot as far as LA-ICP-MS is concerned. Their combination turned out to be quite useful for the investigation of these archaeological materials: the chemical nature of the white, red, brown and black pigments employed in the pottery manufacture was investigated. Iron and manganese compounds were identified as the red and brown/black main colouring substances, respectively; on the other hand, whites and engobes (whitish slips) were based on kaolinite. This set of colouring substances is of importance, as it enabled the artisan to obtain in one oxidising firing cycle brown, black and red paints. Finally, the finding of manganese black in these Canosa potsherds confirms that Canosa was an important centre connecting the near East to central Italy and Europe since the pre-Roman age. Copyright (C) 2010 John Wiley & Sons, Ltd.