We focused on the behaviour of elemental distributions in unglazed earthenware artifacts. The potential role of the elemental depth profiles, as measured using a portable laser induced plasma spectroscopy (LIPS) device, in discriminating between genuine unearthed archaeological findings and modern counterfeits was investigated. Measurements were carried out on a set of ancient unglazed earthenware samples from archaeological excavation and on some corresponding modern artifacts. The analyses pointed out that the elements exhibiting the most significant and repeatable modulations were iron and calcium. A systematic depletion of the former was observed in all the samples analysed, without any possibility of discrimination, whereas calcium had different behaviours. A recurrent presence of high-amplitude, broad, and structured calcium content peaks in proximity of the surface of genuine unearthed samples was measured, a feature that was not observed for modern artifacts. This result provides the first evidence of the possible use of calcium depth distribution measured using LIPS analysis as a marker in authentication studies of unglazed earthenware artifacts.

The use of cadmium chalchogenide nanoprecipitates to obtain brightly coloured glasses enormously expanded by the beginning of the twentieth century, when the production of cadmium-based pigments was already well established. Six historical stained glass pieces produced between the late 1920s and modern days have been investigated in order to delineate the average size and the elemental composition of the nanocrystals. As non-invasive conditions are now mandatory when considering objects belonging to cultural heritage, Raman spectroscopy is used to measure the (average) elemental composition of the nanoparticles. Zinc substitution is also detected by the shifting of the Raman peak position. Moreover, a tentative evaluation of size distribution and crystallinity of the nanoparticles has been performed considering those parameters that are mainly influenced by the disorder of the system, such as Raman band width, surface phonons and the ratio between second and first order band intensities. A confirmation of the above-mentioned conclusion is searched by means of transmission electron microscopy (TEM) and local elemental analysis. Raman investigations allowed identifying a different and more pronounced disorder characterizing the oldest glasses, also verified by TEM observations, suggesting a different manufacture. This article is part of the themed issue ‘Raman spectroscopy in art and archaeology’.

The characterization of archaeological ceramics according to their chemical composition provides essential information about the production and distribution of specific pottery wares. If a correlation between compositional patterns and local production centers is assumed, pottery manufacturing and trade and, more generally, economic, political, as well as cultural relations between communities and regions can be investigated. In the present paper, the combined application of portable XRF and statistical analysis to the investigation of a large repertory of ceramic fragments allowed us to group the assemblage by identifying geochemical clusters. The results from the chemical and statistical analysis were then compared with reference ceramic samples from the same area, as well as with macroscopic and petrographic observations to confirm, coalesce or sub-divide putative sub-divisions. The study of 141 samples from different sites located within a wide area spanning across the Colline Metallifere and the coast (Monterotondo Marittimo, Roccastrada, Donoratico, and Vetricella) provided new clues for a new interpretive archaeological framework that suggests that there was a well-defined organization of pottery manufacturing and circulation across southern Tuscany during the early medieval period.