Good conservation and restoration practices of cultural heritage assets rely on the knowledge of original materials. In the framework of the HERACLES Project (HERACLES—HEritage Resilience Against CLimate Events on Site, H2020 Grant Agreement 700395), dealing with the effects of climatic actions and natural hazards on built heritage, a set of important heritage sites are currently under study to improve their resilience against climate events. Among these are the medieval Gubbio Town Walls in Italy. The present work focuses on the mortars and binders of this monument and collected samples related to different parts of the Walls, corresponding to various historical periods of construction and interventions. They were characterized to determine their minerochemical composition, thermal behavior, and morphology. For that purpose, ex-situ laboratory techniques, such as X-ray diffraction (XRD), wavelength dispersive X-ray fluorescence (WDXRF), optical microscopy (OM), polarized light microscopy (PLM), scanning electron microscopy (SEM), and simultaneous differential thermal analysis and thermogravimetry (TG-DTA) were used to discern trends in different sampling areas due to construction/reconstruction periods and building techniques.

The study of building materials constituting cultural heritage is fundamental to understand their characteristics and predict their behavior. When considering materials from archaeological sites, their characterization can provide not only relevant information for a broader understanding of the site and its importance and significance but can also increase knowledge about ancient materials and their performance. The Palace of Knossos is a very important archaeological site in the European history context, and its preservation benefits from the characterization of the constituent materials. Samples of mortars from this monument were collected under the scope of the H2020 HERACLES project, where a multi-analytical approach was chosen using established protocols for the different sample typologies. Instrumental techniques such as optical microscopy (OM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and simultaneous thermogravimetry and differential thermal analysis (TG–DTA) were used for the chemical, mineralogical, and morphological characterization of these mortar samples. The results indicate that the majority are lime mortars, both aerial and hydraulic, but gypsum-based mortars were also identified. Differences in the chemical composition of the samples in distinct areas of the monument allowed us to reflect on the variety of materials used in the construction of the Palace of Knossos.

The glazed tiles that paved the apse of the Monastery of St. Mary of Alcobaça were a rare decorative element in the most important part of this Cistercian construction. These medieval tiles, all monochromatic, are believed to be a thirteenth-century production and represent some of the first examples of tin-opacified glazed tiles in Christian Portugal. Although lead glazes have been extensively used in medieval pavements in North-Western Europe, opaque tin-glazes are far scarcer. The technology used in this case is a testimony of mixing cultures, combining Cistercian Order traditions of building materials and techniques with the Islamic tin-glazing technology brought to the Iberian Peninsula in the tenth century. These glazes were applied on tiles of several geometric shapes to achieve the final decorative effect. For the first time, these tiles were analytically characterized to determine the chemical composition of the different colours of glaze and these differences were assessed to explain the variety of colours and shades observed. The analytical techniques used were µ-PIXE (micro-particle-induced X-ray emission), µ-Raman spectroscopy and optical microscopy. Samples selected for this study comprise all colours observed in Alcobaça tiles: white, turquoise, brown and several shades of green. Results show that the variety of colours and shades are consistent with different proportions of CuO, Fe₂O₃ and SnO₂ in a lead-glazed matrix, together with a K-feldspar-rich white inner layer, most likely to be a slip.

The sheltered environment of the Algares +30 level adit (underground mine gallery) contributes to the preservation of secondary water-soluble minerals formed on the tunnel walls. The massive sulphide and related stockwork zone are hosted by the Mine Tuff volcanic unit and are exposed in the walls of the gallery, showing intense oxidation and hydrothermal alteration. Minerals from the halotrichite group were identified on the efflorescent salts, typically white fine-acicular crystals but also on aggregates with dark orange/brownish colour. Mineral characterization was performed using several methods and analytical techniques (XRD, XRF-WDS, SEM-EDS, DTA-TG), and the chemical formulas were calculated maintaining the ratio A:B ≅ 1:2 in accordance with the general formula of the halotrichite group, AB₂(SO₄)₄·22H₂O. This methodology allowed the assignment of the orange colour to the presence of trivalent iron on iron-rich pickeringite in partial substitution of aluminium.

The Monastery of Alcobaça houses in reserve the ceramic tiles that adorned the floor of the church's apse. These tiles were removed during rehabilitation works and many preserve part of their original fixing mortars. A comprehensive analysis of 21 samples was conducted using a multi‐analytical approach (X‐ray fluorescence, X‐ray diffraction, scanning electron microscopy–energy‐dispersive X‐ray spectroscopy, μ‐Raman spectroscopy, thermogravimetry–differential thermal analysis, optical microscopy, and colorimetry). Results suggest compositional variations in the samples from the back and sides of the ceramic tiles; however, the mineralogy and general characteristics of the aggregates remained consistent between the samples and are coherent with the local geology, suggesting a shared historical origin.

Coated fabrics featuring plasticised poly(vinyl chloride) (p-PVC) and thermoplastic polyurethane (TPU) coatings are widespread in fashion collections. These materials pose significant conservation challenges due to their production and chemical variability, coupled with issues of rapid deterioration. Despite their prevalence and instability, systematic research on their composition and ageing behaviour remains limited, as most studies rely mainly on infrared spectroscopy and cover a small number of cases, which cannot fully capture their chemical complexity. This knowledge gap represents a pressing issue, as it hampers the development of well-informed conservation strategies. This research addresses this gap by investigating a representative set of twenty-five historical and contemporary fabrics from the 1990s onwards, coated with aromatic and aliphatic polyester-based TPUs, as well as phthalate- and terephthalate-plasticised PVCs. Samples were characterised using a multi-analytical approach combining optical microscopy, infrared spectroscopy, pyrolysis–gas chromatography/mass spectrometry, and X-ray fluorescence spectroscopy. This integrated strategy provided unprecedented detail on the chemical variability of p-PVC and TPU-coated fabrics, enabling the identification of primary components, additives, degradation products, and mixed compositions. This study underscores the value of multi-technique analysis to capture the complexity of such coated fabrics, providing essential knowledge for further research and development of effective conservation strategies for fashion collections.