The Iulia Felix is a 2nd-century AD Roman shipwreck that was discovered off the coast of Grado in 1986. Following its recovery, the hull was dismantled and treated with high concentrations of PEG 4000 at elevated temperatures. This process was completed in 2003. The elements were then stored for over 20 years. During this prolonged storage period, salt efflorescence developed on some surfaces, raising concerns about ongoing degradation and prompting an investigation into the composition of the wood and how environmental conditions influence it. The efflorescence was analysed using scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS), X-ray powder diffraction (XRPD) and Fourier transform infrared spectroscopy (FTIR). To evaluate the impact of environmental factors, samples were exposed to controlled humidity levels of 35% and 85% until equilibrium was achieved. The analyses identified iron- and sulphur-based compounds, including hydrated ferrous sulphates, calcium sulphate and hydrated iron oxides. These findings suggest a corrosion-related degradation process that originates in a marine burial environment and progresses in humid, oxygen-rich conditions after recovery. The presence of PEG within the efflorescence indicates that environmental conditions after treatment promoted its gradual migration to the surface. Climate testing revealed that PEG 4000 significantly reduced hygroscopic exchange with the environment. Under dry conditions, dimensional changes were minimal, with less than 1% variation in mass and surface area. In contrast, prolonged exposure to high humidity resulted in a 11% increase in mass due to moisture uptake, as well as a roughly 5% increase in surface area. This was accompanied by minor cracking and, in some cases, structural failure. This study highlights the long-term conservation challenges posed by waterlogged archaeological wood treated with high-molecular-weight PEG. It emphasises the importance of continuous environmental monitoring to mitigate degradation processes and preserve structural integrity, providing valuable insights for future museum conservation strategies.

The present study investigates the effects of various cadmium-based pigments on the curing behaviour of linseed oil. Model linseed oil paints, prepared starting from different cadmium yellow pigments, were subjected to accelerated aging inside a thermobalance at 80 °C, under oxygen flow and in the dark. Thermogravimetric analysis (TGA) was used to monitor the mass change of the paint samples induced by oil autoxidation during curing, while ATR-FTIR spectroscopy provided insights into molecular transformations before and after thermal exposure. Results reveal that cadmium yellow pigments with identical chemical composition (CdS) can induce different curing kinetics, depending on the crystalline features of the pigments, namely crystallite size and degree of crystallinity. Pigments having nanocrystalline structures delayed the onset of peroxide propagation, resulting in extended induction times and incomplete polymer network formation in the timeframe investigated. These paints also showed formation of cadmium carboxylates and cadmium sulphates. These results may be related to the intrinsic peroxidase-like (POD-like) catalytic activity of nanocrystalline CdS, reported here for the first time in a non-aqueous medium.

An X-ray Absorption Spectroscopy (XAS) and Electron Paramagnetic Resonance (EPR) investigation of protohistoric blue vitreous materials was undertaken, aimed at ascertaining the valence state speciation of Cu and Co, suspected to play a role in the colour origin. Five different glass artefacts coming from Paduli (Colli sul Velino, Rieti, Italy) were investigated. A bichrome blue and white vessel fragment represents the only Natron glass. The other four beads, instead, are LMHK glass. A relevant question deals with concentration, distribution, and valence states of the transition elements Cu and Co. Two out of the five colored objects, in fact, contain only Cu, whilst the others exhibit both Cu and Co. A sample holder was specifically designed to ensure minimal invasiveness during XAS measurements. Multiple measurements (up to six) were performed for each sample at the Cu and/or Co edges to verify sample homogeneity. Fragments of the samples, when available, were investigated by EPR without manipulation to further characterize the CuII aliquot in the materials. The XAS spectra provided significant information confirming the presence of the CoII chromophore in the samples where this species is chemically more abundant, and identifying and quantifying the presence of the CuII chromophore. CuII, as revealed by EPR, appears in a distorted (4 + 2)-fold coordination and partly clustered to form pairs. This spectroscopic approach, combining XAS and EPR techniques, proves to be successful in the characterization of Co- and Cu-based blue colors in the glasses of the Bronze Age, highlighting the high skill reached in the production.

This paper presents an emerging diagnostic protocol for the study of modelling pastes in monumental terracruda sculpture, a distinctive technological tradition of monumental sculpture in air-dried clay. The study combines some newly acquired analytical data from Uzbek case studies with previously published results, integrating them with textual and ethnographic evidence to establish a diagnostic framework for material characterization and conservation decision-making. The proposed approach builds on a circular process of comparison and feedback between different sources of knowledge (archaeometric analyses, historical textual evidence, and traditional practices) each informing and refining the others. This interdisciplinary synthesis allows the identification of functional and compositional variations within historical examples and provides the basis for interpreting regional and chronological patterns in the production of terracruda sculpture. By formalizing this integrative workflow, the paper aims to define a reproducible methodological framework for future studies and conservation strategies concerning monumental terracruda sculptures preserved in archaeological and historical contexts, as well as dispersed fragments held in museum collections worldwide. (c) 2026 The Author(s). Published by Elsevier Masson SAS. This is an open access article under the CC BY license ( http://creativecommons.org/licenses/by/4.0/ )

This paper presents the results of a multidisciplinary research project carried out over the past two years by the Archaeological Mapping Laboratory at the CNR-ISPC, Lecce, and the Heritage Materials Science group at the CNR-ISPC, Florence, in collaboration with the PASAP Med Ph.D. Programme at the University of Bari “Aldo Moro”. The investigation focuses on stone procurement strategies employed by the Messapian settlement at Ugento, near the Ionian coast of Salento. Archaeological surveys within its territory and surrounding areas enabled the identification and petrographic characterization of ancient extraction sites, allowing for the classification of several calcarenite types. Systematic sampling and petrographic analyses of archaeological specimens shed light on the sourcing strategies adopted for both the construction of the city’s defensive walls—erected in the mid-4th century BCE—and selected architectural and sculptural elements preserved in the Ugento Archaeological Museum and the Colosso Collection, dating from the Archaic to the Hellenistic periods. The analyses show that the availability of lithotypes in the region significantly influenced construction techniques, particularly in the city walls, while in certain cases—such as specific architectural elements made of pietra leccese—it required the import of lithologies absent from the immediate vicinity.

The historic center of Florence, situated along the Arno River, has endured various geohydrological disasters, including floods and landslides. Riverbanks were built for city defense and dates back to ancient times. This study focuses on the investigation of the mortars of three Florentine riverbanks – Lungarno degli Acciaiuoli, Lungarno delle Grazie, and Lungarno Torrigiani – from mineralogical-petrographic, physical, and mechanical perspectives. These riverbanks, crucial for protecting the city from floods, exhibit distinct characteristics in terms of construction, materials, and historical developments. Analysis revealed similarities and differences of raw materials and constructive techniques. Petrographic and mineralogical analyses highlight the presence of various minerals and aggregates, indicating the use of traditional techniques and materials such as Pietra Alberese for lime production. TGA and SEM-EDS techniques further confirm the hydraulic behavior of the mortars. Overall, this study offers valuable insights into the construction and preservation of historical riverbanks, contributing to the conservation of cultural heritage in Florence.

A one-hundred-year-old hypothesis regarding the transfer of the brick building technology from Lombardy to Denmark by the mid-1100’s has been tested. Two churches in Denmark and two in Italy have been re-examined by their architectural traits. 305 brick samples have been analysed by TL-dating, magnetic susceptibility, TL-sensitivity, XRD, FTIR, XRF, LA-ICP-MS, and spectrophotometric colour measurements. Mortar samples have been analysed by Py-GC-MS and thin section examination allowed a comparison of the manufacturing technologies. The scarce historical references on the transfer theory have been re-examined in perspective of the archaeometric evidence. Although not decisive by themselves one by one, collectively our results point to a rejection of the direct transfer hypothesis. Considering the results of the present investigation it seems more likely that the diffusion of knowledge about brick building technology followed a more convoluted path from the Cistercian communities in Lombardy towards Denmark with stops underway, likely in Germany.

In heritage science, preparing mock-ups is often a fundamental yet challenging aspect of experimental protocols. This work arises from the need to understand the critical factors that must be considered when preparing model oil paint layers. Specifically, the focus is on understanding the rheology and the curing process of oil paints, and the work was carried out selecting ultramarine blue as pigment and (semi)drying oils as binder. The factors investigated here are the types of pigment and oil, paint thickness, pigment storage conditions, and paint solids content. In this work, 10 different ultramarine blue pigments were selected, differing in terms of their origin (natural and synthetic), particle size distribution, presence of coating or additives, and overall composition. Cold pressed walnut, safflower and linseed oils were used, as well as linseed oils subjected to different pre-treatments, i.e., stand oil and alkali-refined oil. The rheological behavior of fresh model paints was investigated, focusing on the effect of parameters such as pigment particle size distribution and water content. Fresh model paints were also analyzed with ThermoGravimetric Analysis (TGA) under air flow at a constant temperature (80 degrees C), and some selected paints with microUV-Pyrolysis-Gas Chromatography-Mass Spectrometry (microUV-Py-GC-MS). This enabled us to compare the induction period of the curing reactions, as well as the balance between oxidative degradation and polymerization when the paint formulation was systematically varied. Results show how, in the case of ultramarine blue, the natural pigments behave differently from the synthetic ones, both from a rheological and from a chemical point of view. The study demonstrates that all the parameters investigated strongly affected both the rheology and the chemical curing of the oil paints, which must thus be taken into consideration when carrying out systematic studies. (c) 2025 Elsevier Masson SAS. All rights are reserved, including those for text and data mining, AI

Recent excavations at the Phoenician coastal site of Tell el-Burak, a large-scale agricultural production centre in use during 725-350 BCE, have uncovered the first Iron Age wine press in Lebanon. This discovery enabled a systematic, interdisciplinary study of its plaster, offering insights into ancient construction technologies. The analysis extended to two other plastered installations found in separate rooms within the complex, allowing for a comprehensive comparison. An integrated program of archaeometric analysis, including optical microscopy in polarising light, X-ray powder diffraction, scanning electron microscopy, thermogravimetry, and organic residue analysis, was applied to samples from these three structures to investigate plaster composition and technological variability. Previous studies identified the use of crushed ceramic fragments in a lime-based plaster. Now, new analyses provide deeper insights into the nature of the binder, revealing how the addition of ceramic sherds may have enhanced the plaster's mechanical properties and hydraulicity, making it a significant early example of hydraulic mortar. These findings confirm the existence of a local, innovative tradition of lime-plaster manufacture in southern Phoenicia. This investigation not only sheds light on the specific technological practices of Tell el-Burak, but also contributes to the broader understanding of Phoenician and Punic technological advancements in the Iron Age Mediterranean.

The binder of the ancient natural hydraulic mortar is obtained by firing marly or siliceous limestone, which is naturally rich in clay minerals or silica. The setting and hardening process of these mortars is complex, as is their composition, which varies depending on the raw materials, the environment of preservation, and the age of the material. Natural hydraulic mortars from important religious and historic buildings in Florence (i.e. Giotto's Bell Tower, Medici Riccardi Palace and Trebbio Castle) were characterized using conventional techniques (SEM-EDS, TGA, XRPD and ATR-FTIR). In-depth analyses of the binder were performed on the same sample portions through precise sample preparation and the high spatial resolution of advanced techniques, producing high-quality chemical and mineralogical maps. Micro-X-ray powder Diffraction at the European Synchrotron Radiation Facility (SR-μXRPD) and Fourier transform infrared microspectroscopic technique (FPA-FTIR) allow the determination of the distribution and stability of calcium carbonate polymorphs (calcite, aragonite, vaterite) as well as crystalline and amorphous calcium aluminum silicate in the binder of ancient mortars. These results are of fundamental importance for the understanding of ancient production technologies and the chemical transformations that can give these ancient materials their hydraulic behavior. For the first time, SR-μXRPD and FPA-FTIR have been used to study ancient natural hydraulic mortars, demonstrating the complementarity of these high-resolution techniques for mapping compounds in the historic binders.

An interdisciplinary and multi-analytical approach-combining non-invasive and non-destructive with micro-destructive techniques-has been applied, for the first time, to glass artifacts from Central Italy dating from the Middle Bronze Age to the Early Iron Age. This research provides the unique and extraordinary opportunity to investigate glass materials shedding light on ancient glassmaking techniques and tracing the trade networks that shaped the distribution of these artifacts across Central Italy. The non-invasive and non-destructive techniques (i.e. p-XRF, FORS and XRD) provided a preliminary characterisation of all the analysed samples that was used to further identify and select a considerably reduced number of artefacts to be investigated by micro destructive ones (i.e. SEM-EDS and EMPA). The combination of all these techniques allowed to identify two main glass types. The majority of the samples display the chemical composition of LMHK glass (one of which High-K) with several characteristics comparable to those from Northern Italian production centres. One sample displays instead a composition typical of natron glasses, with similarities to glass artifacts produced in the Eastern Mediterranean and Egypt. Two main types of chromophores play a role in the origin of the blue colour, Cu and Co. Sb was used to impart both the opacity and the white coloration. The findings of this work suggests that this archaeological site was included in an international framework of long-distance trade and confirm the importance of the Paduli archaeological site in Central Italy at the end of the II millennium B.C. Here, phenomena of social complexity seem to have emerged with the presence of nascent local elites capable of inserting themselves into the network of international traffic.

The gilded bronze eagles that stand upon the summit of the Tabernacle by Michelozzo in the Abbey of San Miniato al Monte, Florence (Italy) are an exquisite example of Italian Renaissance sculpture. Commissioned by Piero di Cosimo de Medici, the two eagles, representing the ancient Arte di Calimala, were cast and decorated by Maso di Bartolomeo in the 1448–1449 period. A multi-analytical approach was set up to characterize the state of conservation, materials used, and artistic technique of the eagles. Non-invasive methods were used and integrated with micro-invasive analyses, such as X-ray fluorescence (XRF) and Fourier-transform infrared (FTIR) spectroscopy, X-ray diffractometry on powders (XRPD), scanning electron microscopy coupled with EDS (SEM-EDS), and metallographic investigation. The results depict shiny-looking eagles, suggesting the use of oil gilding on almost all surfaces and revealing the presence of polychromies, which is almost unusual in XV-century bronze statuary and is initially hidden by deposits and corrosion products. Indeed, the paws were originally painted with azurite, while the use of cinnabar imparted a vivid red color to the tongue. A black paint containing mercury was found on the eyes and talons. The bales of cloth were decorated with silver, which is now almost completely lost and whose remains are not visible due to being tarnished, while fine details in gold were detected on the lanyard.

Multi-analytical approach to reveal the presence and distribution of lead compounds at the micro-scale level in the red stains on heritage marbles.

Hierapolis of Phrygia, an archaeological site in southwestern Turkey, has been a UNESCO World Heritage Site since 1988. During archaeological campaigns, 71 mortar samples from public buildings were collected, dating from the Julio-Claudian to the Middle Byzantine period. The samples were analyzed using a multi-analytical approach including polarized optical microscopy (POM), digital image analysis (DIA), X-ray powder diffraction (XRPD) and SEM–EDS to trace the raw materials and understand the evolution of mortar composition and technology over time. During the Roman period, travertine and marble were commonly used in binder production, while marble dominated in the Byzantine period. The aggregates come mainly from sands of the Lycian Nappe and Menderes Massif, with carbonate and silicate rock fragments. Variations in composition, average size and circularity suggest changes in raw material sources in both Roman and Byzantine periods. Cocciopesto mortar was used in water-related structures from the Flavian to the Severan period, but, in the Byzantine period, it also appeared in non-hydraulic contexts. Straw became a common organic additive in Byzantine renders, marking a shift from the exclusively inorganic aggregates of Roman renders. This study illustrates the evolving construction technologies and material sources used throughout the city’s history.

The paper deals with the technological aspects of the construction site of Pompeii through the characterization of the mortars, focusing on the identification of raw materials, their supply areas, selection criteria and mixing techniques to evaluate the continuity and changes in the different construction phases. Thanks to a multidisciplinary protocol that integrates archaeological, architectural, minero-petrographic and geochemical analyses, the study reveals that the binders were obtained from burning limestones from Mt. Lattari, while the aggregates are compatible with products from the Somma-Vesuvius volcano. The mortars from the period before 62/63 CE are characterised by a careful selection and preparation of the raw material, while the mortars from the period after 62/63 CE indicate a less precise procedures, probably due to the urgent need for reconstruction after the earthquake. Despite these changes, the essential quality and hydraulic properties of the mortars remained intact, demonstrating the resilience of ancient building practises.

The overarching challenge of this research is setting up a procedure to select the most appropriate fraction from complex, heterogeneous materials such as historic mortars in case of radiocarbon dating. At present, in the international community, there is not a unique and fully accepted way of mortar sample preparation to systematically obtain accurate results. With this contribution, we propose a strategy for selecting suitable mortar samples for radiocarbon dating of anthropogenic calcite in binder or lump. A four-step procedure is proposed: (I) good sampling strategies along with architectural and historical surveys; (II) mineralogical, petrographic, and chemical characterization of mortars to evaluate the feasibility of sample dating; (III) a non-destructive multi-analytical characterization of binder-rich portions to avoid geogenic calcite contamination; (IV) carbonate micro-sample preparation and accelerator mass spectrometer (AMS) measurements. The most innovative feature of the overall procedure relies on the fact that, in case of positive validation in step III, exactly the same material is treated and measured in step IV. The paper aims to apply this procedure to the ancient mortar of the Florentine historical building (Trebbio Castle), selecting micro-samples suitable for dating in natural hydraulic mortars. The discussion of the mortar dating results with the historical-archaeological hypotheses provided significant insights into the construction history of the building.

This work deals with the archaeometric investigation on 25 fragments of terra sigillata (red-coated ceramic ware and moulds) found in the city of Arezzo, Tuscany (central Italy), and attributed to several important workshops from the first century BCE to the second century CE. Optical and spectroscopic techniques were used to analyse both the ceramic bodies and the red slips. All the potsherds showed a very fine-grained ceramic body, sharing similar mineralogical compositions, mainly consisting in quartz, plagioclase, pyroxene, hematite, K-feldspars, and illite/muscovite. The mineralogical data suggest that both the red-coated wares and the moulds were produced using the same calcareous-illitic clay and fired under oxidising conditions at temperatures between 850 degrees C and 1000 degrees C. A K-rich illitic clay with a Fe content around 10-15% (in wt%) was used to elaborate the slips. Al-substituted hematite was found in red slips by micro-Raman spectroscopy. Comparison of the chemical data with terra sigillata from other important production areas in Italy and from other regions of the Meditteranean Sea, allowed to define that the studied samples, locally produced in Arezzo, differ systematically from all others, although they show similarities with nearby Pisan productions as well as those Puteolan.

The analytical and spectroscopic discrimination of marbles coming from quarries used in historical times is a task object of a wide interest in archaeometric investigations. This task is even more difficult, when the goal of the provenance assessment is focused on marbles coming from historical quarries located in a close geographic area. In this paper, we present the results of a systematic Electron Paramagnetic Resonance spectroscopy study aimed at assessing the discrimination criteria among 5 quarries located in the Denizli region (Anatolia, Turkey) that were benefited in Hellenistic and Roman period to provide materials for the buildings in the nearby city of Hierapolis of Phrygia (Turkey). The resulting EPR characterisation is used, in combination with the results of isotope geochemistry and petrological observation, to define criteria able to discriminate the provenance of marble samples from the considered quarries. The criteria arose from the analysis operated through robust compositional statistical techniques over the results of the experimental investigation. In this approach, the internal structure of the multimethodic dataset was unravelled. The results here presented provide evidence of a good discriminating ability of the proposed approach.

ABSTRACTAbsolute dating of plasters and mortars clearly represents a key information to study important structures and buildings that may have undergone a difficult story starting from their construction. This is for instance the case of the architectures in the archaeological site of Hierapolis (Denizli, Turkey). However, when discussing about the possibility to apply radiocarbon (14C) dating, in this site the presence of different sources of contaminants, due to the geological and geochemical conditions and to the used raw materials, prevents the binder dating. As an alternative, we thus decided to focus on the small fragments of straw that had been used as additives in the mortar/plaster matrices. The fragments were identified, selected and dated using a 14C experimental set-up specifically optimized for microgram-sized samples. The obtained results were satisfying, even though the measured 14C ages also pointed out some possible criticalities in dating such small samples collected from a carbonaceous matrix.

Here, we demonstrate, for the first time, the possibility of distinguishing between geogenic and anthropogenic calcite in a non-destructive and effective way. Geogenic calcite derives from natural sedimentary and metamorphic rocks whereas anthropogenic calcite is formed artificially due to the carbonation process in mortars and plaster lime binders. Currently, their distinction is a major unaddressed issue although it is crucial across several fields such as 14C dating of historical mortars to avoid contamination with carbonate aggregates, investigating the origins of pigments, and studying the origins of sediments, to name a few. In this paper, we address this unmet need combining high-resolution micro-Raman spectroscopy with data mining and machine learning methods. This approach provides an effective means of obtaining robust and representative Raman datasets from which samples' origins can be effectively deduced; moreover, a distinction between sedimentary and metamorphic calcite has been also highlighted. The samples, chemically identical, exhibit systematic and reliable differences in Raman band positions, band shape and intensity, which are likely related to the degree of structural order and polarization effects.