THE TECHNOLOGY OF PRODUCTION OF SASANIAN GLAZED POTTERY FROM VEH ARDAŠ?R (CENTRAL IRAQ)

Scanning electron microscopy coupled with an energy dispersive X‐ray detector (SEM‐EDS) has been used to study samples of Sasanian glazed pottery. Analysis of ceramic bodies revealed a general homogeneity in composition among the studied samples and the use of calcareous clay for their manufacture. Glazes are typically alkaline in composition, with sodium and potassium oxide contents between 8 and 13%, and between 3 and 5%, respectively; calcium and magnesium oxide contents are between 7 and 10%, and between 3 and 5%, respectively. These data suggest the use of plant ash together with a silica source for glaze production. Coating thickness is highly variable among different samples, from some 400 up to 1200 µm, but it is generally uniform when a single sample is concerned. Glazes are mostly coloured blue or blue‐green; copper and iron are the colouring agents detected; abundance of bubbles, silicate crystals and relics of unmelted material are responsible for their generally opaque appearance, together with the presence of weathering products. The characteristics of the body to glaze contact zone, together with the widespread presence of bubbles, would not rule out production by a single firing process. A few samples feature a peculiar gritty coating on one side of their surface; SEM images show that they are actually partially vitrified, and EDS data denote a rather heterogeneous composition. It seems possible that they result from mixing clay together with the frit used for glaze development.     

THE CHARACTERIZATION OF WATERLOGGED ARCHAEOLOGICAL WOOD: THE THREE ROMAN SHIPS FOUND IN NAPLES (ITALY)*

Three apparently well‐preserved shipwrecks dating back to Roman times were brought to light near Piazza Municipio in Naples (Italy), during the excavation for the construction of Line 1 of the subway. The shipwrecks were covered by marine sand and silt, below the water table. In order to establish the nature and the extent of wood degradation and, therefore, determine how best to preserve the shipwrecks, a diagnostic investigation was carried out. The study involved the identification of wood species, chemical characterization of the residue component and physical and micro‐morphological characterization.