No abstract

This work concerns the characterisation of a set of wall painting and stucco fragments collected during a rescue excavation carried out in 2013 by the Soprintendenza Archeologica in the Monte d’Oro area (Rome). Due to the contextless archaeological situation, analyses were performed to obtain more information about the collected materials. A multi-analytical approach has been applied including spectroscopic (FTIR, Raman and visible reflectance analyses) and elemental analysis (SEM-EDS) techniques. The chromatic palette has been in this way disclosed evidencing the use of pigments such as cinnabar, Egyptian blue, red and yellow ochre and green earth, but also the simultaneous use of them. The presence of a decoration achieved by using a gold leaf has been highlighted also, indicating the preciousness of the decorations. The convenience and advantages linked to the use of portable instrumentation have been also evidenced.

Roman and Byzantine glass shards collected during excavation campaigns around the ancient city of Thugga in northern Tunisia have been characterised by means of various analytical techniques. Portable X-ray Fluorescence (pXRF) was used to determine the glass matrix elemental composition and to identify the elements responsible for the colour. Fibre optic reflectance spectroscopy (FORS) was employed to investigate the chemical nature, the oxidation state and the coordination of the chromophores. X-ray photoelectron spectroscopy (XPS) was here exploited for characterising the outermost layers of the glasses. Elemental analyses by pXRF pointed out that Si, Fe, Al, Ca, K, Rb, Sr, Na and Mg are the main elements present in the glasses. The chromophores responsible for the different shades are Fe for the green shades, Cu and Co for the blue ones, Mn, also used as discolouring agent, for the colourless samples. In relation to the raw materials used for glass production, the comparison with control groups of samples from Northern Tunisia suggests a common provenance of sands