This article concerns the diagnostic campaign aimed at analyzing the mural painting representing the iconographic theme of the Deesis of the Church of St. Maria Annunziata, Motta San Giovanni, in the province of Reggio Calabria. In 1951, a flood caused the collapse of the building and the consequent breaking of the apse into two parts. The present study focused on the left side of the apse, hosting the figures of Christ and Mary, in order to plan the best conservation intervention strategy. For this purpose, non-invasive investigations and laboratory analytical methods were conducted in order to characterize the constituent materials and to identify the forms of alteration and degradation present on the surface of the painting. In particular, Raman spectroscopy, optical microscopy, scanning electron microscopy coupled to the chemical analysis by an EDS probe, Fourier-transform infrared spectroscopy and ion chromatography were employed. The results highlighted the presence of a single layer of plaster made with a lime-based binder. The chromatic palette of the painting is characterized by ochres and carbon black mixed with lime to obtain the different shades. Finally, the definition of the nature of the deposits and of the overlaid materials was fundamental in order to identify the best products and methods to restore the readability of the work.

This study illustrates the results of minero-petrographic and microchemical investigations of artificial stone materials (mortars, plasters, and bricks) taken from the Theatrum Marcelli (Rome, Italy). To achieve this objective, the artificial building materials were analysed using Polarized Optical Microscopy (POM) and a Scanning Electron Microscope (SEM) used in backscattered electron (BSE) mode and coupled with an Energy-Dispersive Spectrometer (EDS) after a sampling campaign. The POM was aimed at collecting information on the textural and mineralogical characteristics of the samples (identification of the main minerals constituting the aggregate, grain size and shape, and the evaluation of the binder/aggregate ratio). The data also supported technological assessments through the characterization of the raw materials used for the manufacture of the mortars/plasters. Furthermore, the SEM-EDS investigations revealed the chemical composition of both the aggregate and the binder, which was useful for estimating their hydraulicity index (HI). The diagnostic campaign allowed us to obtain interesting information on the plasters/mortars used in the Theatrum Marcelli, together with their probable production technology. In particular, the raw materials were quite homogeneous, thus confirming the traditional methodology used in Roman times to create natural hydraulic mortars by the addition of pozzolanic volcanic material to aerial lime. The volcanic component of the aggregate seems to be compatible with the ultrapotassic products of the Roman Magmatic Province—likely with the Pozzolane Rosse pyroclastic deposit of the Alban Hills district.

This research concerns a stylistic and archaeometric study of an ancient marble female bust recently discovered by the Trapani Lombardo family of Reggio Calabria (Southern Italy) and delivered to the Superintendency of Archaeology, Fine Arts, and Landscape for the metropolitan city of Reggio Calabria and Vibo Valentia (SABAP). Based on the first technical, stylistic, and iconographic observations made by the competent bodies, it is a half-length portrait bust from the Roman era, which precisely had the function of faithfully reproducing the physiognomy of the depicted subject. The research aimed to establish the authenticity of the artwork and the origin of the raw material, providing indications about the textural and compositional features and of the alteration products as well as identifying traces of any previous restoration interventions. For these purposes, after a preliminary assessment of the state of conservation of the bust using visual inspections supported by a handheld digital microscope, different analytical techniques, including polarized optical microscopy (OM), scanning electron microscopy coupled with energy dispersive spectrometry (SEM-EDX), carbon and oxygen stable isotope ratio determinations (δ¹³C and δ¹⁸O), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR), were used. The results highlighted the originality of the artifact, thus remarking on the importance of the precious archaeological find to be included in the cataloging of tangible assets in the panorama of Italian cultural heritage.

This research investigates the potential utilization of rice husk ash (RHA), an agricultural by-product, in lime-based mortars for the conservation of cultural heritage. While RHA has been extensively studied as a supplementary cementitious material in the construction sector, its application in lime-based mortars for the conservation of historic surfaces remains largely unexplored. To address this gap, the research was structured into three phases: (i) production and characterization of RHAs calcined at 500–800 °C; (ii) evaluation of their pozzolanic reactivity in lime pastes; and (iii) formulation and testing of RHA-based mortars. Physico-chemical and microstructural characterization (XRD, XRF, LOI, SEM–EDS, BET) showed that RHA remains predominantly amorphous up to 700 °C, with silica contents above 87%. Among the investigated ashes, RHA calcined at 500 °C (RHA500) exhibited the highest specific surface area and the greatest pozzolanic reactivity, as confirmed by TGA, FT-IR, and SEM–EDS analyses, which highlighted rapid portlandite consumption and C–S–H formation. Based on these results, lime mortars were prepared with 10–50 wt% replacement of hydrated lime by RHA500 and cured under standard and humid conditions. After 28 days, the hardened specimens underwent an experimental program including colorimetric analysis, capillary water absorption and drying behaviour, ultrasonic pulse velocity measurements, bulk density determination, salt crystallization resistance, compressive and flexural strength testing and carbonation depth evaluation. Results were compared with reference air-lime and NHL 3.5 mortars. Data demonstrate that lime-RHA mortars exhibit promising performance, in several cases comparable to that of NHL 3.5 reference mortars, highlighting their potential as compatible and sustainable repair materials for heritage conservation.

The conservation of coastal archaeological sites, like the Roman Villa of Casignana in southern Italy, dating back to the 4th century AD, faces various threats, including erosion, rising sea levels, and urbanization. To preserve this site’s valuable mosaics, a multidisciplinary approach involving archaeology, environmental science, engineering, and community engagement is necessary. The University of Calabria, particularly through its Restoration academic course and Heritage Science research group, focuses on conserving and valorising the Villa. As part of the national PNRR Tech4U project, the Villa of Casignana has been chosen as a pilot site for the development of innovative technologies for the conservation of cultural heritage, also taking into account the evolution of conservation problems related to climate change and the evolution of coastal lines. Once validated in the laboratory, these technologies will undergo field testing. Community involvement and education are emphasized for the sustainable conservation of coastal archaeological sites.