Pigments and Bulk Composition of Pottery Fragments of a Longbard Grave

Information dealing with bulk constituents, ceramic layers and decoration pigments of pottery fragments recovered from a Longbard settlement, were obtained by Scanning Electron Microscopy (SEM) techniques applied to fractured samples. The samples were fractured just before the measurements and so materials of the site where the fragments have been obtained did not contaminate the analysed surfaces, given the brief exposition to air. The samples consisted of two terracottae and a ceramic fragment from graves of the excavation site. The terracottae contained different decorations : the bigger one was decorated with a so-called « brown band » decoration, while the smaller was decorated with a « red band » decoration. The third fragment was a terracotta bulk with a ceramic layer superimposed on it along with a clearly more visible decoration with respect to the other samples. The results show that the bulks of the analysed samples were composed of the usual silicates with very small and peculiar silver grains widely distributed within the bulk of the terracottae. Whilst the ceramic fragment comprises the same bulk structure, its surface layer shows the presence of lead, but no traces of tin have been found in this layer or in the bulk of this sample. In the decoration of this sample, the detection of heavy elements is very scarce. The terracotta fragments have the same bulk structure (including the presence of the silver grains), while the decorations of such samples show the presence of iron in both « brown band » and « red band », with the iron content being greater in the latter band. Interestingly, since red ochre can brownish if it is burnt, no manganese has been detected in both samples so that the « brown band » can be only a burned « red band ». Potassium has been detected only in the « brown band » decoration, this element is totally absent in the « red band » decoration ; instead a higher content of calcium and magnesium has been registered for this decoration. The pigment and composition characterization supplied by our results can help classify the techniques used in manufacturing the pottery.