Characterization of glaze ceramics from the archaeological site of La Alcazaba, Almería (Spain)

The combination of ion beam and nuclear non-destructive analytical techniques performed on these ceramics have allowed the discussion on several aspects of the production technology, as the use of raw materials, and the degradation processes suffered by them. Glaze composition is discussed first. It is characterized by high values of Pb, Sn, Na, K and Mg. Chromophores are identified and some raw materials are discarded (psilomelane for manganese black) or proposed (absolite, skutterudite and trianite for blue). Secondly, the most degraded samples are found to be characterized by high values of Cl, in an inverse relation with the content of Si. The surface of two samples with lustre decorations, one with Cu particles and one with Cu + Ag particles, are studied finding a progressive decrease of Pb in the surface. Finally, the pastes of the samples are characterized by high values of Ca with respect to other ceramics of the area. Similar values are found in ceramics from Manises and Sevilla. The case of a possible imported sample is also discussed.