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A collection of Hellenistic–Roman glyptics, kept at the Regional Archaeological Museum "Paolo Orsi" (Syracuse, Italy), was investigated in situ with portable Raman spectroscopy with the aim of assessing the viability of this approach, not only for the immediate identification of the gemstones but also for a more in‐depth successive data treatment. At the same time, a corroboration of the autoptic identification of the materials, both archeological and belonging to historical collections, was looked for in order to verify and potentially correct what reported in the museum catalogue. Actually, most of the identifications could be confirmed, the glyptics being mainly made of chalcedony. Other materials found were garnet, glass, and amber. The larger group of chalcedony Raman spectra was subjected to principal components analysis treatment that, after appropriate pretreatment, resulted successful in separating spectra with higher or lower contribution of the band due to the presence of moganite and SiOH bonds. The garnet spectra were instead subjected to quantitative study to identify the main end member. Both the quick identifications and the more detailed studies on chalcedonies and garnets were achieved thanks to the nondestructive and noninvasive investigation, directly in situ, with no sample preparation and minimal interference with the museum's activities. [ABSTRACT FROM AUTHOR]

Zeolites are present in numerous outcrops of volcanites of different ages in Sicily (Italy). Some of these outcrops are important because they constitute the ideal genesis conditions of some of these minerals, which represent geological indicators of chemical and geothermal gradients involved during their formation. For this purpose, a group of zeolites coming from areas of the Ionian coast and Palagonia village (Eastern Sicily) was investigated by means of Raman spectroscopy. In the geological record, these areas have been influenced by intense volcanic events that produced mineralization of hydrothermal origin. Sicilian zeolite samples were analysed in situ using different mobile Raman apparatus, directly on the outcrops of Aci Castello and the nearby Lachea Island, or in local collections where they are preserved. Some of these samples have been then analysed using laboratory micro‐Raman to compare the results and identify the zeolite types. The strength and weakness points of each instrument have been highlighted. Often, the Raman spectra of zeolites are affected by broad fluorescence, making them of difficult interpretation. However, satisfying results were obtained with portable devices, whose identifications were confirmed by micro‐Raman, discerning zeolites of different groups, such as analcime, chabazite, natrolite and phillipsite. The use of portable instruments has demonstrated the possibility to obtain identification of zeolites and related minerals both on site and in the laboratory, whose results match with the geological setting of the considered areas. [ABSTRACT FROM AUTHOR]

Tanzanite is the blue to violet‐blue variety of the sorosilicate zoisite; its colour is due to vanadium substitution of aluminium in the octahedral sites and is proved to appear after natural or artificial heating to approximately 500°C. Its colour makes it a highly appreciated gemstone, for this reason often imitated or thermally treated with the aim of enhancing its hue. Tanzanite loose gemstones are easily identified by classical gemmology methods that are not always applicable to mounted jewels. At the same time, zoisite Raman spectra are rarely reported in literature and never with a systematic approach. In this work, zoisite samples and cut tanzanite gemstones were considered, with the aim of filling this gap by addressing different methodological aspects. Namely, the orientational effects were investigated to explain the spectral variability, the photoluminescence bands were differentiated from the Raman signals using different excitation wavelengths, and the effectiveness of portable instrumentation in the correct identification of tanzanite was evaluated. The results are encouraging, showing that zoisite is revealed, notwithstanding orientational effects, by both portable and laboratory Raman instruments with comparable performances, opening the way to an effective identification of mounted tanzanite gemstones. Furthermore, the employ of different excitation wavelengths allowed to distinguish the photoluminescence bands with both categories of devices, thus identifying rare earth elements (REEs) likely associated with the mineral's genesis. [ABSTRACT FROM AUTHOR]

Alkali‐activated materials (AAMs) and "geopolymers" are inorganic polymeric materials obtained by mixing of solid aluminosilicate precursors with an alkaline solution (generally, KOH or NaOH and Na2SiO3 mixed in various ratios). This class of aluminosilicate materials has emerged as a greener alternative to traditional concrete, for large‐scale as well as for niche applications such as conservation and restoration of built heritage. In this work we apply Raman spectroscopy both to aluminosilicate precursors (metakaolin, pumice, volcanic ash, volcanic soils, clayey sediments, ceramic waste) and to the respective AAMs. In the field of vibrational spectroscopy, Raman is much less employed in the literature with respect to Fourier transform infrared (FTIR) to have insights into the alkali activation process from a molecular point of view. The aim of this paper is to investigate the potentiality of a Raman approach to the comparison of the employed raw materials with the respective AAMs. Raman analyses during the first hours of geopolymerization were also carried out on the clayey sediments and ceramic waste‐based products. The results, differentiated according to the employed precursors, exhibit spectra relative to crystalline and amorphous phases that can give an indication about the newly formed aluminosilicate gel. [ABSTRACT FROM AUTHOR]

Archaic Roman painted antefixes, architectural slabs and louteria from the Palatine Hill in Rome, Italy, were studied by non‐destructive and micro‐destructive methods: Portable X‐ray fluorescence (XRF), micro‐Raman spectroscopy, optical microscopy, scanning electron microscopy with energy‐dispersive spectroscopy (SEM‐EDS) and X‐ray diffraction (XRD). The investigation enabled the characterization of raw materials and ceramic technology, providing insights on provenance. In fact, similarities were recognized with terracottas from the neighbouring Etruscan Veii. The analysis of pictorial layers revealed the use of Fe‐ and Mn‐based pigments, as well as the identification of more precious pigments on worthy pieces. The research intended to support the archaeological discussion about the frame of the nascent city of Rome, also in relation to the coeval Etruscan culture. [ABSTRACT FROM AUTHOR]

An analytical investigation performed on Southern Italy pottery highlighted the usefulness of Raman spectroscopy to give answers to archaeological questions. It can provide important information concerning the production technology and raw materials constituting the glassy coatings. Raman spectroscopy was supported by Scanning Electron Microscopy coupled with Energy Dispersive X‐ray Spectroscopy (SEM‐EDS) for observations and elemental analysis. The studied samples, ranging from the 13th century lead‐tin‐glazed protomajolica to the 15th –16th enamelled pottery, come from the Castles of Montella and Ariano Irpino (Campania), from the castles of Scicli and Modica and from surveys carried out in Buscemi and Caltagirone (Sicily). Glassy matrices, opacifying agents, colour‐related raw materials and body‐coating interface crystalline phases were investigated. Though the coatings resulted all typically lead‐rich glass types, lumps showing a different Raman profile suggested that at least in one case, the batch was adultered with recycled glass waste. Furthermore, samples coming from Montella, belonging to the three main classes of ceramics defined by archaeological hypothesis, could be grouped according to their cassiterite content. The crystallization of lead–potassium feldspars at the coating‐body interface in a group of samples was ascertained. With regard to the origin of colours, the spectra of blue coatings highlighted phases that can be traced back to the use of Co‐based and Co–As‐based raw materials, while turquoise decorations were found to contain malayaite. Highlights: Medieval and renaissance pottery from Southern Italy were analysed.Raman analyses provided unexpected results and answers to archaeological questions.SnO2 Raman bands confirmed the grouping of Montella samples in three classes.Neoformed phases due to reactions during the production processes were discovered.Different cobalt‐based phases were found in the blue enamels. [ABSTRACT FROM AUTHOR]

In the last decade, Raman spectroscopy has been used for routine investigation for gemmological purposes, being non-destructive and non-invasive. In addition, this technique grants short measurement times without any sample preparation. In this context, this work is focused on the spectroscopic characterization of different kinds of blue gems, including sapphires, by comparing the performance of a handheld Raman instrumentation along with a micro-Raman spectrometer, with the aim to provide gemmological certification and to get information on the provenance of the gems. The main goal of the present study is to identify imitation gems and to distinguish between natural and synthetic sapphire; in this latter case, micro-Raman measurements were fundamental for the characterization of the inclusions. Moreover, the chemical composition of blue gems has been obtained by portable XRF technique. The obtained data show that a portable Raman spectrometer can be recommended as a fast and easy instrument to discriminate sapphire from imitations. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

In recent years, the use of Raman spectroscopy as a gemological tool has largely increased, in particular in the conservation science field where a non-destructive and contactless identification is required. In this work, we show the large amount of information which is possible to obtain with Raman analysis on one of the most important gems, emerald, the green variety of beryl. In particular, 14 not certified faceted emeralds have been studied by means of a standard micro-Raman spectrometer, allowing also the identification of some fakes (garnet, glass, and quartz). All the emerald gems have been fully characterized from the vibrational point of view. In particular, the high frequency spectrum, in the OH region, has been exploited to estimate the amount of alkali ions present in the channels of the crystalline structure. In addition, solid and fluid inclusions have been identified and were useful to hypothesize the provenance of the mineral. The shape and position of the characteristic laser-induced luminescence of chromium ions have helped to better define the origin of the gems. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

In this paper, a multi-technique approach, at different scale of observation, is used to characterize a group of decorative stones and to permit to distinguish rocks with similar aspect but coming from different areas. In particular, the samples under study are sedimentary and metamorphic rocks, widely used as building blocks of modern and historical constructions and sculptures. The petrographic and mineralogical features of such rocks were performed by optical microscopy and Raman and Fourier transform infrared absorbance spectroscopies. These techniques permitted to obtain a complete structural, textural, and mineralogical characterization. At elemental level, the investigation was carried out by X-ray fluorescence (XRF). In particular, XRF and Raman measurements were collected using portable instrumentations, whose advantages for the in situ analysis have been pointed out. The obtained results evidenced the high discriminant capability of the portable XRF for the decorative stones especially when this method is coupled with mineralogical and petrographic information. In this context, we propose to create a database for precious ornamental stones, which could be a starting point for a non-destructive characterization, even useful for provenance study and/or certification of origin. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Micro-destructive and non-destructive X-Ray fluorescence techniques and scanning electron microscopy coupled with energy-dispersive spectrometry have been applied for the analysis of ten samples of Hellenistic black-varnished pottery, coming from archaeological excavations in Syracuse and Adrano (South Italy, Sicily). Micro-morphological and compositional investigations, together with statistical data processing, have shown several differences among the varnishes of the specimen found in the two sites. In particular, Syracuse varnishes are characterised by a more homogeneous composition and well-defined raw materials, whereas Adrano samples show a higher variability, probably linked to the use of different raw materials and the poorer quality of the varnish as well. The obtained results attest that, as Syracuse black pottery is concerned, the production technique is at an advanced level, whereas Adrano manufacture seems to be less specialised. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The preciousness of historical artifacts leads to the performance of nondestructive and/or microdestructive analyses, especially when the archeological finds are stored in museums. The PXRF spectrometry represents a powerful technique for the chemometric study of the materials, in alternative to the more usual destructive X-ray-based methods. A large set of limestones belonging to several formations cropping out in the Hyblean area (south-eastern Sicily, Italy) was analyzed by means of a PXRF instrument. The main goal was to test the PXRF potentiality for the discrimination of rocks with similar features and to create a chemical database of carbonate rocks, which were commonly used in the past in the manufacturing of sculptures and stone artifacts. Fluorescence data were processed by means of multivariate statistical analysis. In particular, principal components analysis and linear discriminant analysis were applied. The results allowed us to classify the samples belonging to different formations and to distinguish different rock typologies within each formation. Finally, the investigation showed that the analytical PXRF data can be suitable for a substantial characterization of stone materials and this could be extended to museum materials belonging to cultural heritage. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The present work reports a detailed investigation on the speciation of iron in the pigments of decorated pottery fragments of cultural heritage relevance. The fragments come from the Gioiosa Guardia archaeological site in the area of the `Strait of Messina' (Sicily, Southern Italy), and date back to VI-V century BC. The purpose of this study is to characterize the main pigmenting agents responsible for the dark-red coloration of the specimens using non-destructive analytical techniques such as synchrotron radiation X-ray absorption spectroscopy (SR-XAS), a well established technique for cultural heritage and environmental subjects. Absorption spectra were collected at the Fe K-edge on the Italian beamline for absorption and diffraction (BM8-GILDA) at the European Synchrotron Radiation Facility in Grenoble (France). In order to determine the speciation of Fe in the samples, principal component analysis and least-squares fitting procedures were applied to the near-edge part of the absorption spectra (XANES). Details on the local structure around the Fe sites were obtained by analyzing the extended part of the spectra (EXAFS). Furthermore, an accurate determination of the average Fe oxidation state was carried out through analysis of the pre-edge peaks of the absorption spectra. Samples resulted composed of an admixture of Fe2O3 (hematite or maghemite) and magnetite (Fe3O4), occurring in different relative abundance in the dark- and light-colored areas of the specimens. The results obtained are complementary to information previously obtained by means of instrumental neutron activation analysis, Fourier transform infrared absorbance and time-of-flight neutron diffraction. [ABSTRACT FROM AUTHOR]

On the axial zone of the Southern Apennines the major tectonic boundary between the inner platform (Western platform unit) and the pelagic (Lagonegro units) domains is represented by a thick level of highly deformed rock-assemblage. Structural analysis reveals that this tectonic unit represents an intracontinental melange complex characterized by a block-in-matrix fabric that contains blocks from both hangingwall platform and footwall basin units. This unit comprises different sets of structures that, caused by shearing processes, developed at depths ranging from about 8–9 km to the surface. These tectonites represent the product of a crustal shear zone developed at the major boundary between platform-basin domains of Adria during the thick-skinned tectonic processes controlling the Southern Apennines mountain building. [ABSTRACT FROM AUTHOR]