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The importance of preventive conservation strategies for the built heritage has been debated in the last years, but there is still a limited number of applied researches involving complex architectural sites. The identification and monitoring of the decay processes after the restoration activities can support future preventive conservation strategies. In this study the colorimetric approach made on the facades of Palazzo Margherita, US Embassy Rome's Chancery building is presented. This monument situated in the center of Rome (Italy) is an important case study for the understanding of the interaction between the surfaces and the environment. The main conservation issues have been identified and studied. A non-invasive colorimetric monitoring of selected areas of the facades has been carried out over a two-year period in order to evaluate the measurements of detected surface colour changes using the statistical PCA technique to represent the data.

Salt crystallization is widely recognized as a cause of deterioration of porous building materials. In particular, the crystallization pressure of salt crystals growing in confined pores is found to be the main cause for damage. The aim of this study is to better understand the degradation of porous rocks induced by salt crystallisation and correlate such processes with the intrinsic characteristics of materials. With this intend, an experimental salt weathering simulation has been carried out on two limestones widely used in the Baroque architecture of eastern Sicily. A systematic approach including petrographic, porosimetric and colorimetric analyses, was used to evaluate the correlation among salt crystallisation, microstructural and chromatic variations of limestone. Results showed a quite different resistance of the two limestones to salt damage, and this was found to be strongly dependent on their pore structure and textural characteristics.

The Tomb of the Diver has been subject for many decades of fierce debate among archaeologists and classicists. Since its discovery in 1968, some scholars have considered it a unique example of the lost tradition of Greek painting, others have emphasized Etruscan or Italic parallels. More recently, a possible local production has been suggested. With the aim of trying to solve the archaeological question, an archaeometric comparison among this well-known artwork and several frescoed tombs coming from Hellenistic and Lucan necropolis was carried out. The multi-analytical study was focused on the identification of peculiar features of executive techniques and raw materials since the first period of the archaeological site. The analytical investigation has been preliminary based on a non-destructive approach, performed in-situ by portable equipment including imaging diagnostics and compositional spectroscopic techniques for identifying pigments and the conservation state of original painted surface; subsequently, a further deepening by using destructive techniques was performed in-lab for the mortar-based supports characterization. Archaeometric study suggested that technological choices slightly changed in a time span of about two centuries, highlighting important markers that allow clustering the contemporary artistic productions. Moreover, a comparison with mortars from temples decorations was provided to better understand the whole artistic context. The archaeometric data showed that the Tomb of the Diver could be traced back to a local artisanal tradition and therefore is neither Etruscan nor Greek, but the first and foremost an expression of the local elite culture of Paestum.

San Domenico Church was built between 1441 and 1468 and represents one of the most important historical buildings of the Cosenza area (Calabria, Southern Italy) thanks to its architectonic style and the works inside, such as the “Madonna della Febbre”, a notable marble altar dated back to the XVI century. The church, as well as the sculptural group, underwent various interventions over time, unfortunately scarcely documented; thus, in this paper, the characterization of six white marble samples coming from the altar, was carried out to determine their provenance. The samples were analyzed by means of complementary methodologies well known in the archaeometric field: polarized optical microscopy (POM); an electron probe micro analyzer coupled with an energy dispersive spectrometer (EPMA-EDS); inductively coupled plasma–mass spectrometry (ICP-MS); and isotope ratio mass spectrometry (IRMS). The results provided important information about the “Madonna della Febbre” altar, suggesting the presence of different typologies of marbles and hypothesizing their possible provenance, including Carrara and Docimium. It was not clear if these marbles were re-used materials but, regardless, the reported information adds precious elements to the history of the entire architectonic complex, providing new issues to be deepened.

This paper presents the first results about the provenance of obsidian fragments recovered in the archaeological site of Samshvilde (South Georgia, Caucasus) with the aim to obtain knowledge related to the network distribution and procurement of obsidian in Georgia. The geochemical characterization of thirty archaeological finds was obtained by the LA-ICP-MS method, an almost non-destructive technique capable of chemically characterizing the volcanic glass. A comparison of geochemical results obtained on both archaeological artefacts and geological samples collected from Chikiani outcrop in Georgia, together with literature data of southern Caucasus and eastern Turkey, allowed us to define the source of the archaeological obsidians of Samshvilde site. The majority of archaeological samples (28/30) shows a local provenance, precisely from Chikiani (Georgia) on the contrary the other two samples suggest a provenance from two different Armenian sources respectively Gegham and Akhurian volcanic system.

The Western civilization is deeply rooted in the Ancient Greece culture, political, scientific, technological and philosophic knowledge were born in this epoch. Their diffusion was improved upon by the Greek expansionist policy in colonies of Magna Graecia in Mediterranean Basin, leaving important archaeological traces for the community. In this context, the European project &ldquo, MAGNA, on the route from Greece to Magna Graecia&rdquo, seeks to develop a transnational thematic touristic route between Greece and the Ionian coast of Calabria (Southern Italy), an ancient Magna Graecia colony, on the basis of cultural and historical connections between these two Mediterranean areas. The project aims to promote the touristic development of the Greek and Calabrian archaeological sites through dissemination activities. These will concern scientific subjects regarding the conservation of cultural heritage, both in sub-aerial and underwater environments, and study of the sea floor, and pollution of seawater by microplastics. This touristic product consists of cruises on a ship equipped with scientific instruments that offer unique cultural experiences, accompanied by multimedia supports. Experts drive people in the proposed activities, creating more awareness of sustainable and responsible tourism.

This study aims to assess the different decay phenomena affecting the Cosenza Cathedral façade (Calabria, South Italy) through the evaluation of the relative damage indices. For this goal, a multidisciplinary approach was applied exploiting both nondestructive and microdestructive techniques. Such a combination enabled proposing an intervention priority scale that can be helpful to institutions when planning a prompt restoration intervention. The results suggest the efficiency of this approach to obtain a multidisciplinary diagnostic and conservation system for the management and valorization of the Cultural Heritage also in terms of monitoring, maintenance, and selection of the most suitable restoration procedures over time.

The use of stone materials in cultural heritage and architecture represents a practice that has its roots in ancient times. Stone buildings, depending on the construction materials and their location in the urban context, are particularly vulnerable to weathering phenomena. These can be often accelerated by changes in environmental conditions linked mostly to the anthropic activities. In this way, the present work is addressed on the minero-petrographic and geochemical characterisation of samples taken from the built historical heritage in Cairo (Egypt), related to seven monumental areas. These sites have been chosen based on their historical importance, type of material, state of preservation and position in the Cairo context. The construction materials used and their degradation products were studied comparing the results obtained by means of different analytical techniques such as polarised light optical microscopy (POM), ion chromatography (IC), Fourier transform infrared spectroscopy (FT-IR) and the carbonaceous fraction, detected by using the thermogravimetry (TG). The results achieved demonstrated that black crusts and salt crystallisation represent the most common and damaging degradation products affecting all the monumental sites. Moreover, the environmental pollution produced by industrial activities and vehicular traffic has been identified as the main cause of these processes, followed by a marginal contribution of natural sources such as the sea spray. The data collected provide useful information to plan efficient conservation strategies in the future.

The consolidation and protection of mud bricks are a challenge in the field of conservation of archeological sites. One of the solutions is represented by the coverage of the entire excavation that assures a protection against mud dissolution. Unfortunately, this is not always feasible, both for economical and practical issues. For these reasons, alternative solutions are needed. In this work, laboratory experimentation has been carried out in order to test the efficacy of some products to slow down the dissolution process and increase the brick toughness. Three typologies of raw materials taken from different outcrops (one from the Republic of Azerbaijan and two from Calabria region, Italy) have been characterized and used to build mud brick specimens. Four consolidation treatments were tested (ethyl silicate, potassium silicate, potassium hydroxide, sodium hydroxide) and different investigations have been performed to check their efficiency against the dissolution in water. Results suggested that the efficacy of each treatment is related to the main intrinsic characteristics of the raw material employed for the mud bricks manufacture. Among the tested products, nanolime and NaOH solution showed very poor performance, while ethyl silicate and KOH could be very promising compounds for successful conservation.

The Archaeological Museum of Palermo (Sicily) has recently presented the results of the restoration of three wall paintings from the House of the Masks of Solunto archaeological site. These significant paintings, dating back to the first century BCE, are the most significant examples of Pompeian style discovered in Sicily to date. The cycle of frescoes unearthed is the best preserved and most complete example of wall painting dating to the Republican Roman period in Sicily. This house was a luxurious private residence built on two floors and centred around a peristyle. This fresco cycle embellished the walls of a banquet room (oecus) discovered during an archaeological excavation carried out by Giovanni Patricolo in 1869. The House of the Masks definition was suggested by Salemi Pace in 1872 when he published the discovery of frescoes with colourful garlands and theatrical masks. In 1874, five panels were detached from the walls and moved to the National Museum of Palermo for conservation purposes. The recent careful cleaning of the pictorial surfaces and the new archaeological and archaeometric research revealed unusual details about the pictorial technique and newly painted subjects. The scientific investigation was preliminarily based on a non-destructive approach, performed in situ using portable equipment and subsequently, the further examination of a micro fragment using micro-destructive investigation. X-ray fluorescence analysis was carried out to identify the original pictorial palette, and electron microprobe analyses coupled with energy-dispersive X-ray spectroscopy to define the alteration products. Finally, infrared imaging provided new data about the pictorial technique and iconography. The new archaeometric evidence sheds light on these rare examples of Roman wall painting in the Sicilian Roman province, which until today have not been systematically studied from the point of view of materials and execution techniques, confirming the dating and connections with contemporary workshops active in other Roman provinces.

In this work a combined laboratory-based and neutronographic investigation was carried out on a type of limestone, known as Pietra di Lecce stone, widely used in Italian Baroque as construction material. The limestone was treated with two different commercially-available coatings, namely nanosilica and nanolime, and artificially weathered by salt crystallization and temperature/relative humidity jumps. The aim was to provide an experimental evidence of the protective and consolidating effectiveness of the two treatments by looking at the water absorption process occurring inside the pore network of the analyzed stones. The analysis of the wetting front position revealed significant variations in the water absorption kinetics among the investigated samples, suggesting different mechanisms of interaction between the inorganic consolidants and the underlying bulk stone. Finally, a quantitative evaluation of the best effectiveness of the two products was addressed, particularly useful in view of an appropriate choice of restoration procedures to be applied to building materials.

Neutron radiography (NR) was here applied to study the effects of two different commercially available consolidants on the water absorption properties in a particular type of limestone (biocalcarenite), known as Pietra d’Aspra stone, which is one of the most extensively used lithotypes in Sicilian Baroque buildings. Our attention was mainly focused on the evaluation, using a fast and nondestructive visualization of water motion through capillarity, of the effectiveness of such layers as consolidating agents in view of preserving and maintaining both old and modern structures. The biocalcarenite was treated with nanosilica (Nano Estel®) and nanolime (CaLoSil®) by brushing it until full saturation, and then artificially weathered by salt crystallization and temperature/relative humidity jumps. Liquid distribution and height of the water front were monitored as a function of time. Significant differences in the water suction behavior among all the investigated samples were highlighted, which allowed us to gain insight into the coating/substrate interaction mechanisms which regulate the fluid mobility inside the porous network of the limestone.

This multidisciplinary research focuses on diagnostic investigations to characterize the archaeological materials, as well as the alteration and degradation forms detected at the Roman Thermae of Reggio Calabria (Calabria, South Italy) site. The thermal complex, (dating I–II century B.C.), was built around three main rooms such as the caldarium (hot bath), the tepidarium (warm bath) and the frigidarium (cold bath), all connected to a central room through several entrances. The central hall still preserves a suggestive mosaic floor dating between the II and III century A.D., characterized by geometric motifs and black and white tesserae. Fragments of various archaeological stone materials, such as bricks, mortars, sedimentary, volcanic and metamorphic rocks have been studied with different and complementary techniques. Particularly, polarized optical microscopy (POM) and X-ray diffractometry (XRD) were performed to characterize the materials employed to construct the site and evaluate their state of preservation. Finally, laboratory microbiological culture analysis was conducted to identify the main microorganisms composing the biological patinas detected on the sampled materials. Results allowed us to evaluate the most suitable restoration procedures to conduct at the archaeological site, considering the different stone materials present in the studied area and their state of conservation.

Tituli Picti are an ancient form of urban graffiti very common in the archaeological site of Pompeii (Naples, South—Italy). They are generally made of red pigments applied on walls of Campanian ignimbrite. This paper deals with a scientific investigation aimed to their conservation. This is a challenging task since it requires a multidisciplinary approach that includes restorers, archaeologists and conservation scientists. The study has provided suggestions on the proper way to conserve Tituli Picti over time. In the present work, several specimens of Campanian ignimbrite were painted with red earth pigment; lime and Arabic gum have been used as binders as well. Such painted stones were treated with three consolidants: a suspension of reactive nanoparticles of silica, ethyl silicate and an acrylic microemulsion. Treated and untreated specimens were subjected to thermal aging, artificial solar radiation and induced crystallization decay. It has been assessed the colorimetric variations induced by treatments. Moreover, the micromorphologic features of the consolidated surfaces have been highlighted by means of electron microscope observations. The scotch tape test allowed to compare the superficial cohesion induced by the three used products. According to the results, ethyl silicate seems to represent the most successful product.

In the last decades, many researchers investigated the relation between environmental pollution and the degradation phenomena on the built heritage, because of their rapid increase and growing harmfulness. Consequently, the identification of the main pollution sources has become essential to define mitigation actions against degradation and alteration phenomena of the stone materials. In this way, the present paper is focused on the study of the effect of air pollution on archaeological buildings in Historic Cairo. A multi-methodological approach was used to obtain information about the chemical composition of examined black crusts and to clarify their correlation with the air pollution, specifically the heavy metals and the carbonaceous fraction, their main sources, and their impact on the state of conservation of the studied sites. All specimens were characterized by polarized optical microscopy (POM), X-Ray Diffraction (XRD), Electron Probe Micro Analyser coupled with energy dispersive X-ray spectrometry (EPMA-EDS), laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and Thermo-gravimetric analysis (TGA). The study conducted on heavy metals and carbonaceous fraction showed that the greatest contribution of the accumulation of pollutants is attributable to vehicular traffic and industrial activities, the main polluting sources in Cairo city. Furthermore, the comparison with other studies conducted on the carbonaceous fraction in the black crusts coming from both European and non-European cities, has allowed to discriminate the contribution of the primary and secondary polluting sources. Finally, the correlation of the data obtained on the heavy metals and the carbonaceous fraction allowed to formulate important hypothesis about the processes of sulphation.

This archaeometric study deals with seven samples of prehistoric pottery and, for the first time in Georgian studies, thirteen samples of glazed medieval pottery. All specimens were collected at Samshvilde, the most remarkable archaeological complex in southern Georgia and believed to represent locally-manufactured products. Two additional samples of raw materials composed of clay, silt, and sand were collected near the site and used to compare composition. Several analytical techniques were applied: Optical Microscopy (OM), Scanning Electron Microscopy (SEM), Electron Probe Microanalysis (EPMA), X-ray Diffraction (XRD) and X-ray Fluorescence (XRF). The results allowed to build a complex scenario in terms of exploitation of raw materials and technological choices. The raw materials indicate a volcanic environment and correspond to the geological settings of the territory of Samshvilde. The glazed ceramics were characterised as alkali, low alkali – low lead, lead, high lead and tin-opacified mixed-alkaline lead glazes. The compositional comparisons extend from east to west and place these ceramics in the wider framework of Islamic ceramics.

This paper presents the results of a laboratory experimentation carried out on stone materials in the framework of the CRATI project (Knowledge and Restoration through Advanced Integrated Technologies) aimed at testing new products with consolidating properties by means of an integrated methodological approach. After the preliminary characterization of stone materials collected in the pilot site, the second stage of the activities within the project were focused on the formulation and testing of products for the conservation of the same materials against decay, especially salt crystallization, one of the most aggressive and common degrading processes. The San Domenico Church, located in the old town of Cosenza (Calabria, Southern Italy) has been chosen as the pilot site and for the in situ tests. Several specimens with the same features of the stone materials used in San Domenico church were collected from a historical quarry near the city of Cosenza. These specimens were treated and then artificially degraded by salt crystallization tests in order to evaluate their susceptibility to weathering intensity. Three different consolidating products were used, respectively, two commercial and another one formulated in laboratory: (a) a suspension of nanosilica (Nano Estel&reg, ), (b) a suspension of nanolime (CaLoSiL&reg, ), and (c) a suspension of nano calcium-hydroxide dispersed in isopropyl alcohol and then mixed with diammonium hydrogen phosphate. A systematic approach, including minero-petrographic, geochemical and physico-mechanical techniques, was applied to evaluate (a) the nature and main features of materials, (b) the efficacy of consolidating treatments, and (c) the resistance of treated stone to the salt crystallization processes. The tested products demonstrated a significant efficiency to consolidate and protect stone material samples, enhancing their resistance to salt crystallization. Thus, such a case history may be useful in order to plan appropriate restoration interventions that consider the interactions between the building stone and the protective/consolidating product.