Raman and SEM-EDS insights into technological aspects of Medieval and Renaissance ceramics from Southern Italy

An analytical investigation performed on Southern Italy pottery highlighted the usefulness of Raman spectroscopy to give answers to archaeological questions. It can provide important information concerning the production technology and raw materials constituting the glassy coatings. Raman spectroscopy was supported by Scanning Electron Microscopy coupled with Energy Dispersive X-ray Spectroscopy (SEM-EDS) for observations and elemental analysis. The studied samples, ranging from the 13th century lead-tin-glazed protomajolica to the 15th -16th enamelled pottery, come from the Castles of Montella and Ariano Irpino (Campania), from the castles of Scicli and Modica and from surveys carried out in Buscemi and Caltagirone (Sicily). Glassy matrices, opacifying agents, colour-related raw materials and body-coating interface crystalline phases were investigated. Though the coatings resulted all typically lead-rich glass types, lumps showing a different Raman profile suggested that at least in one case, the batch was adultered with recycled glass waste. Furthermore, samples coming from Montella, belonging to the three main classes of ceramics defined by archaeological hypothesis, could be grouped according to their cassiterite content. The crystallization of lead-potassium feldspars at the coating-body interface in a group of samples was ascertained. With regard to the origin of colours, the spectra of blue coatings highlighted phases that can be traced back to the use of Co-based and Co-As-based raw materials, while turquoise decorations were found to contain malayaite.

Automated summary

An analytical investigation on Southern Italy pottery using Raman spectroscopy revealed the importance of this technique in addressing archaeological questions, particularly related to the technology and raw materials of glassy coatings. The study identified different raw material compositions and production processes, effectively distinguishing various classes of pottery.