Search

• Natural ultramarine blue pigment (Lapis Lazuli or Lazurite) photo-catalytically degrades a linseed oil binder, similarly to the effects of synthetic ultramarine blue. • Sodalite pigment also acts as a photo-catalyst, despite the absence of enclathrated polysulfur radical anions. • The zeolitic aluminosilicate cage structure, present in ultramarine blue as well as Sodalite, and not the enclathrated sulfur species are responsible for the photo-catalytic effect. • Relatively stable synthetic binders are less affected by the presence of ultramarine blue. Photo-catalytic degradation of a linseed oil binder by natural ultramarine (Lapis Lazuli or Lazurite) and Sodalite in paint layers was studied. Both pigments degrade the binder under xenon arc exposure, leading to erosion of the binder at the surface, increased roughness, light scattering and desaturation of the color. Both pigments behave similarly to synthetic ultramarine blue studied earlier. The results for Sodalite provide further proof that the zeolitic nature of the aluminosilicate cage causes the catalytic degradation and that the enclathrated polysulfur radical anions S 2 -. and S 3 -. trapped inside the cage are not responsible for the catalytic action. Relatively stable synthetic binders are less affected by the presence of synthetic ultramarine blue. The paints were aged in a xenon arc apparatus using a simulated indoor environment (radiation > ca. 320 nm). The samples were analyzed using diffuse reflectance spectroscopy in the UV–vis and short wavelength infrared (SWIR) ranges, Raman spectroscopy, field-emission gun scanning electron microscopy (FEG-SEM) and FTIR. [ABSTRACT FROM AUTHOR]

The application of multivariate analysis is extremely useful when dealing with large datasets and can be applied also in provenance studies. In this work, Principal Component Analysis (PCA) was applied for the first time to the study of the provenance of lapis lazuli rocks used for glyptic art in ancient times, on a database including four different sources in Afghanistan, Tajikistan, Siberia and Myanmar. Results of the application of PCA on µ-PIXE data collected in mineralogical phases contained in lapis lazuli rocks, in particular diopside and pyrite, confirmed the role of some trace element contents as characteristics for different provenances, i.e. as provenance markers. As an additional important result, PCA seems to strengthen the role of previously found weaker markers (i.e. trace elements not sufficient alone to distinguish univocally among provenances) such as, for example, the coexistence of high Ti, V, Cr and Mn concentrations in diopside in Afghan lapis lazuli. This can be relevant when other discriminant phases like pyrite cannot be found in the sample or are not suitable for analysis. Moreover, for geological purposes and to try to distinguish among different quarries inside an extraction area, a study on intra-provenance variability was carried out on diopside data for Myanmar and Siberian samples. The separation into three groups for Myanmar samples, previously identified by means of minero-petrographic and elemental analysis, is confirmed and a partial differentiation was identified also for samples coming from the two Siberian areas of Sludyanka River and Malaya Bistraya River. [ABSTRACT FROM AUTHOR]

The idea of ionoluminescence 3-D imaging is introduced to provide surface structural information of luminescent samples from a depth of tens of micrometers. Application of broad ion beam in an in-air setup results in capturing high resolution 2-D images in short times. Therefore, ionoluminescence 3-D imaging is a non-destructive technique which can extract information such as inhomogeneity, porosity and roughness, especially from historical precious samples. In order to display the capabilities of the ionoluminescence 3-D imaging technique, the 3-D image of an inhomogeneous lapis lazuli sample is produced based on stereo-ionoluminescence approach. The results are indicative of high potentials of the applied imaging technique for revealing surface structural information of luminescent samples. [ABSTRACT FROM AUTHOR]

Ultramarine blue paint layers in oil paintings can be affected by ultramarine 'disease' or 'sickness': a phenomenon described by a grey appearance and a loss of detail in the artwork. An explanation for this phenomenon is an interaction between the organic binder network and ultramarine pigment, with the pigment acting as a catalyst for the breakdown of the network. This breakdown results in micro-cracks in the paint film, which influences the appearance of the artwork. To investigate the possible catalytic property of ultramarine pigment, a test reaction – the dehydration of methanol to dimethyl ether – was carried out, with and without ultramarine pigment present in a micro-reactor with in-line gas chromatography mass spectrometry. It was observed that a higher yield of dimethyl ether was obtained in the presence of ultramarine pigment, confirming that ultramarine pigment possesses catalytic properties similar to commercial zeolitic silica-alumina catalysts. [ABSTRACT FROM AUTHOR]

The mineral Lapis Lazuli exhibits three thermoluminescence (TL) peaks approximately at 140, 260 and 370 °C. The TL intensity of the three peaks grows with radiation dose and it saturates only beyond 9 kGy. Electron Spin Resonance (ESR) studies have been carried out to identify the defect centers responsible for the thermoluminescence peaks. The ESR spectrum of the as-received natural sample presented the typical six signals due to Mn 2+ ion and a large signal around g=2.030 due to Fe 3+ ion. Room temperature ESR spectrum of irradiated Lapis Lazuli shows the formation of a defect center. This center (center I) is identified as an F + - center (singly ionized oxygen vacancy) and seems to correlate with 140 and 250 °C TL peaks. An additional defect center is observed during thermal annealing experiments and this center (center II - assigned to F + -center) appears to originate from an F -center (oxygen vacancy with two electrons). This F -center, precursor of center II, may be related to the observed high temperature 360 °C TL peak in Lapis Lazuli. [ABSTRACT FROM AUTHOR]

Natural heterogeneous lapis lazuli has been investigated using the complementary techniques of ionoluminescence spectroscopy, ionoluminescence microscopy and micro-PIXE. The equivalent probed depths, the possibility of simultaneous use and the capability of non-destructive in-air application suggest the combined use of ionoluminescence and micro-PIXE techniques as an appropriate approach in mineral analysis to reveal the texture, chemical composition, and elemental distribution of the samples. In this research work, the various mineral phases of a lapis lazuli sample were detected and analyzed. It was possible to identify most of the minerals in the analyzed area, including apatite, a mineral phase uncommon in lapis lazuli, and point out different luminescence features of crystals of the same mineral, diopside, found in different parts of the same lapis lazuli sample. [ABSTRACT FROM AUTHOR]

This work will present preliminary results concerning the use of time-resolved ion beam induced luminescence applied to provenance studies of lapis lazuli. Measurements were performed at the pulsed beam facility at LABEC laboratory in Florence. Lapis lazuli is a semi-precious gemstone, used as ornament since the early civilizations that can be found in few places on Earth. The importance of this work lies in understanding the origin of various samples of lapis lazuli, from which it may be possible to gain insight into trade routes from ancient times. The samples studied in this work originated from Chile, Afghanistan, Tajikistan, Myanmar, and Siberia. The stones were irradiated with 3 MeV protons and the resulting luminescence was detected by a photomultiplier tube, whose output was acquired using a sampling digitizer VME module (CAEN/V1720). Wavelength discrimination was performed at 430 nm utilizing a range of beam currents. The results showed that, by changing the beam current intensity, one can study different features of lapis lazuli, and this may aid in distinguishing lapis lazuli from different provenances. [ABSTRACT FROM AUTHOR]

Lazurite, the blue mineral found in lapis lazuli, may be a marker for the identification of provenance. Sulfur K-edge X-ray absorption near edge structure spectroscopy (XANES) of lazurite from lapis lazuli of various locations, such as Afghanistan, Russia, Chile, the USA, Iran, Tajikistan, and Myanmar, is described. The XANES spectra reveal that several different sulfur chemistries exist within lazurite, attributed to contributions from multiple sulfur species. A peak at 2482.5 eV is attributed to sulfate; an envelope of peaks between 2470 and 2475 eV is attributed to polysulfide radicals, polysulfide dianions, neutral sulfur, and/or thiosulfate; and a peak at 2469.1 eV is attributed to the trisulfur and/or disulfur radical(s). Also, a peak of unknown origin arises at 2466.3 eV in several spectra. The spectral profile for the envelope of peaks (2470 to 2475 eV) varies between samples and in some instances, within a sample. Most notably, the studied samples from Chile display two distinct peaks near 2471.7 and 2473.5 eV with a local minimum at 2472.5 eV, unlike the most commonly observed pattern—that typically observed for samples from Afghanistan—with a single maximum intensity near 2472.5 eV. Other more subtle variations in this energy range also correlate with provenance at varying degrees. [ABSTRACT FROM AUTHOR]

Recently, developments have been made to the external scanning microbeam of INFN-LABEC laboratory in Florence. A new system for mechanical sample scanning was implemented. This system allows us to acquire large maps (up to 20 × 20 cm 2 ), of great interest in the Cultural Heritage field. In parallel, the possibility of using carbon microbeams for experiments, such as, for example, ion beam modification of materials and MeV Secondary Ion Mass Spectrometry, has been investigated. As a test application, Particle Induced X-ray Emission with carbon microbeams has been performed on a lapis lazuli stone. First results for both wide area imaging and external carbon microbeams are briefly reported. [ABSTRACT FROM AUTHOR]

The first part of this study reports on the wide campaign for the extension of the database of both trace and minor elements concentration in diopside by means of μ-PIXE measurements and of luminescence spectra in diopside and wollastonite by means of μ-IL measurements. Diopside and wollastonite are actually two of the most common lapis lazuli-forming minerals. For this former part of the study, we analysed rocks of known provenance at the microbeam line of the LNL laboratories in Legnaro (PD) of the Istituto Nazionale di Fisica Nucleare (INFN). The latter part of the paper is dedicated to the non-invasive Ion Beam Analyses (IBA) characterisation of six pieces of the “Collezione Medicea”. The collection is exhibited at the Museum of Natural History (University of Firenze) and belonged to the Medici family. It includes artworks made of lapis lazuli manufactured in the 16 th and 17 th centuries but there is not precise information about the provenance of the used raw material. Results on the artworks show, as expected, that the Chilean provenance of the material used for the analysed artworks has to be excluded. Lapis lazuli used for five of the analysed artworks can be ascribed to the Afghan quarry district, while one object cannot be attributed only on the base of diopside and wollastonite analysis. [ABSTRACT FROM AUTHOR]

Highlights: [•] Raman spectroscopy has been used to differentiate between genuine and fake lapis lazuli. [•] The spectra were readily acquired in-situ without alteration or destruction of the sample. [•] The results offer a special role for portable Raman spectroscopy in forensic art analysis. [Copyright &y& Elsevier]

Lapis lazuli is among the earliest and most priced ornamental stone worked to produce carvings, beads and inlays as early as the 4th millennium BC. It is an heterogeneous rock composed of blue lazurite Na3Ca(Si3Al3O12)S mixed with other minerals like calcite, diopside and pyrite. The historical source of lapis lazuli in antiquity is supposedly located in Afghanistan, in the Sar-e-Sang district, while other sources are known in Tajikistan and Russia (Baïkal area). This work focuses on the lapis-lazuli of the Egyptian treasure of Tôd dated from Middle Kingdom (20th c. BC). Deposited in four copper boxes, it consists of thousands of blocks of raw lapis lazuli, minute fragments, beads and carvings stylistically dated to various periods. This discovery raises the question of the use of lapis lazuli in ancient Egypt because there is no source of lapis in this country. In addition, most of the lapis lazuli artefacts are strongly weathered. The aim of this work is to understand the alteration process and to verify if its provenance can still be determined. A few artefacts were analysed using the new external microbeam line of the AGLAE facility of the C2RMF. The mineral phases were identified and corresponding trace elements (e.g. Ti, As, Ni, Ba) were ascribed using the quantitative PIXE elemental maps collected on the entire artefacts or on cross-sections. In parallel, the IBIL spectrum recorded for each point in the image provided an additional fingerprint of the luminescent phases, notably mineral species belonging to the cancrinite group. Most alteration products appeared to derive from the oxidation of the pyrite FeS2. It was observed that the alteration process extends to the core of most investigated artefacts. Despite such a strong alteration state, the chemical fingerprints recorded on the studied artefacts proved to be consistent with that of lapis lazuli from historical deposit of Badakshan, Afghanistan, previously investigated using the same μ-PIXE/μ-IBIL protocol. [ABSTRACT FROM AUTHOR]

Abstract: The pigments on the painted pottery figurines from two tombs of Northern Wei Dynasty (AD 386-534) in Luoyang were analyzed by Raman microscopy. All the pigments were identified compared with the Raman spectra of standard pigments. The red pigments were identified as haematite, the blue pigment as lapis lazuli, the green pigment as malachite, the black pigment as carbon black and the white pigment as calcite. Similar pigments were used in the two tombs despite the pottery figurines were very different in artistic style. The use of lapis lazuli as blue pigment on Chinese painted pottery figurines was found for the first time. This pigment and the painted pottery figurine of Sogdians are of great archaeological significance because it demonstrated that the trade and cultural exchanges via the Silk Road had extended to Luoyang city in the Northern Wei Dynasty. The result also confirms that micro-Raman spectroscopy is a powerful analytical method for the identification of pigments on ancient artworks. [Copyright &y& Elsevier]

Abstract: A species observed in aqueous sulfidic solutions at high T and P has recently been identified as the anion radical S3 −, based on the Raman spectrum obtained in a hydrothermal diamond–anvil cell (Pokrovski and Dubrovinsky, 2011, Science, 331, 1052–1054). Such a species had not been expected to occur in such environments, although S3 − as an component of lapis lazuli, other solids and even albite melt has been well studied (Winther et al., 1998; Reinen and Lindner, 1999; Arieli et al., 2004; Shnitko et al., 2008; Bacci et al., 2009). We have calculated the structures, energetics, vibrational and UV–visible spectra of S3 − and several other similar species and confirm the species identification of Pokrovski and Dubrovinsky, although we are still somewhat concerned about the apparent lack of a third peak which we calculate to be present in the Raman spectrum of S3 −. Our calculations indicate that the reaction: in aqueous solution has a free energy change of +3kcal/mol at 298K and 1atm pressure but −13kcal/mol at 723K and 1atm pressure, consistent with the disappearance of disulfide species and the appearance of S3 −at high T. Likewise, the free energy for the reaction: decreases from 44.1 to 19.0kcal/mol between 298 and 723K (again at 1atm). This is consistent with the decrease in concentrations of SH− and SO4 −2 and the formation of S3 − observed by Pokrovski and Dubrovinski over this temperature range. The corresponding log K values are in semiquantitative agreement with those found by Pokrovski and Dubrovinsky. The main contribution to these changes in reaction free energy with temperature come from the VRT (vibrational–rotational–translational) contribution to the gas-phase free energy, while the hydration free energy difference changes little. Calculation of 34S–32S isotopic fractionations for S3 − at 298K give δ values of around +4.3% relative to H2S, a value intermediate between that of S3 and S3 −2. Calculated free energies for exchange reactions between S3 − and SH− establish that S3 − forms complexes with Cu+ which are similar in stability to its complexes with SH−. The S3Cu(OH2) complex shows two coordination at Cu and a nearly linear

Abstract: This work describes the application of infrared spectroscopy combined with chemometric tools for the characterization of the proteinaceous binding media used in medieval paints. Historically accurate reconstructions of the most common binders and binder mixtures used in medieval illuminations (egg white, egg yolk, parchment glue and casein glue) were made. Red and blue colors based on vermilion and lapis lazuli were selected as reference paint samples. These two colors were very widely used in medieval illuminations. Different chemometrics methods (supervised and unsupervised), applied to infrared spectral data, were evaluated in terms of their accuracy in the characterization and quantification of complex binding media formulations of the red and blue paints. Principal components analysis and hierarchical cluster analysis revealed that the Cing absorption region (3000–2840cm−1) and the ester-amides region (1760–1495cm−1 ) were the best wavenumber region for discriminating the different proteinaceous binders. A regression analysis using classical least squares and partial least squares regression allowed the quantification of binder composition in red and blue paint reconstructions. The restriction to the ester-amide absorption region presented the best spectral reconstruction error and the lowest binder composition reconstruction error. [Copyright &y& Elsevier]

Abstract: Two Byzantine VI century manuscripts known as Vienna Dioskurides and Vienna Genesis, held in the Austrian National Library at Vienna, were analysed with in situ non-invasive techniques. Raman spectroscopy, UV–Vis diffuse reflectance spectrophotometry with optic fibres and X-ray fluorescence spectrometry were used to characterise the palette of these early Middle Ages manuscripts. The analytical study was performed to have a better knowledge on the colourants used by ancient miniature painters, a subject known more on the basis of traditional sources (i.e. medieval treatises) than of analytical evidences. Indeed these illuminated manuscripts are, to the authors’ knowledge, among the oldest ever being analysed, so that the colourants found in them can be considered among the oldest evidences of their use. The main feature of Vienna Dioskurides and Vienna Genesis palettes is their richness, exemplified by the simultaneous presence of gold and ultramarine blue; in Vienna Dioskurides cinnabar is also present. Information regarding ultramarine blue is surprising, being the analytical evidence of the use of this precious pigment at least three centuries before its use in Western manuscripts, a feature justified by the fact that the Byzantine Empire was the dominant culture in early Middle Ages in the Mediterranean World. Other colourants include azurite and indigo, red lead, orpiment, red and yellow ochres, while a mixture of blue and yellow colourants, known as vergaut, was used to render green hues. Organic colourants were also used, such as madder and Tyrian purple, the latter employed to dye the parchment of Vienna Genesis. [Copyright &y& Elsevier]

Abstract: In this paper we report about the micro-PIXE characterisation of lapis lazuli, for a provenance study of this semi-precious stone, used for glyptic as early as 7000years ago. The final aim is to find markers permitting to identify the origin of the raw material coming from three quarries in regions of historical importance: Afghanistan, Pamir Mountains and Siberia. This may help to reconstruct trade routes, especially for ancient objects for which written testimonies are scanty or absent at all. Due to the heterogeneity of lapis lazuli we concentrate our attention on single phases instead of the whole stone; in particular we focused on two of the main phases: lazurite, responsible for the blue colour, and diopside, the most frequent accessory mineral. This study was preceded and completed by means of microanalysis with Scanning Electron Microscopy (SEM-EDX) and Cold-Cathodoluminescence (cold-CL) analysis. Despite the limited number of analysed samples, results are sufficient to exclude/suggest a few features as provenance markers, partly confirming what has been previously published in literature. [Copyright &y& Elsevier]

Abstract: Rocks are widely represented in cultural heritage materials. They constitute the major part of archaeological artefacts like stone carvings, tools and weapons, and are present in art works in various forms, such as precious stone inlays or paint pigments. The study of such geomaterials, which are usually constituted of a complex aggregate of mineral phases, aims at determining their exact nature, their provenance and at understanding their possible alteration. Since minerals are often composed of light elements, IBA techniques such as PIXE and PIGE, thanks to their ability to measure with high sensitivity elements down to lithium, should be well adapted to their analysis. However, the bulk composition classically obtained using macro-IBA on pelletized samples or using a broad beam hides the multi-phased nature of the rocks and considerably blurs the searched chemical fingerprint. In contrast, the small size of a nuclear microprobe allows imaging the chemical composition at a finer scale and, when implemented in air, appears ideally suited to analyse without sampling these often precious items. This paper illustrates chemical micro-imaging of rocks with examples performed with the AGLAE external nuclear microprobe: characterisation of microscopic inclusions in gems and detailed chemical mapping of rocks with special emphasis to lapis lazuli. Lapis lazuli is of particular interest in both archaeology and art history: after being employed in Asia since the 7th millennium BC to make carvings and beads, it was used in Medieval Europe as a precious blue painting pigment known as ultramarine. The chemical imaging of major and trace elements in lapis lazuli using external μ-PIXE has permitted to identify its mineral phases, to assign their trace elements and to evidence undetected elements. In combination with μ-XRD and μ-Raman spectrometry, this approach provides a clear mineralogical fingerprint useful to determine rock provenance and to authenticate artefacts of unknown origin. These encouraging results call for the generalization of this non-destructive approach to the study of other heterogeneous materials in art and archaeology. [Copyright &y& Elsevier]

Abstract: The application of micro-Raman spectroscopy (μ-RS) and scanning electron microscopy (SEM)/energy dispersive X-ray spectrometer (EDS) to the research of pigments collected from Statues of Feixiange Cliff No. 67 and No. 69 niche of Tang Dynasty in China is reported. Five kinds of pigments were found in the experimental data, including black (carbon), white (gypsum+quartz), blue (lapis lazuli) and green (Paris green+Barium sulphate). After synthesized in 1814, Paris green was reported for a large import as a light and bright green pigment to paint architectures in China from the late 19th century. The analyzed blue pigment demonstrated the similar Raman spectra to the Lâjvardina blue glazed ceramics, which indicated lapis lazuli was an artificial product. This confirmed the painting of Feixiange Cliff in the early Republic of China as the historical record, and also reveals that some pigments were imported from abroad. [ABSTRACT FROM AUTHOR]

Abstract: Pulsed laser induced breakdown spectroscopy (LIBS) and Raman spectroscopy were performed using a novel laboratory setup employing the same Nd:YAG laser emission at 532nm for the analysis of five commercially available pigments collectively known as “ultramarine blue”, a sodium silicate material of either mineral origin or an artificially produced glass. LIBS and Raman spectroscopy have provided information regarding the elemental and molecular composition of the samples; additionally, an analytical protocol for the differentiation between natural (lapis lazuli) and artificial ultramarine blue pigments is proposed. In particular LIBS analysis has allowed the discrimination between pigments on the basis of peaks ascribed to calcium. The presence of calcite in the natural blue pigments has been confirmed following Raman spectroscopy in specific areas of the samples, and micro-Raman and optical microscopy have further corroborated the presence of calcite inclusions in the samples of natural origin. Finally multivariate analysis of Laser induced breakdown spectra using principal component analysis (PCA) further enhanced the differentiation between natural and artificial ultramarine blue pigments. [Copyright &y& Elsevier]

Abstract: The source of the previously unassigned weak band at 2340cm−1 that is occasionally observed in the infrared spectrum of natural lapis lazuli pigment is here attributed conclusively to CO2 trapped in the β-cage of lazurite. In addition, the geo-sourcing potential of this infrared feature for lapis lazuli is tested and found to be more ambiguous than previously suggested. The CO2 absorption band is in fact observed in lapis lazuli samples from numerous disparate geographic locales including Afghanistan, Canada, Myanmar, Siberia, Tajikistan, and the Ural Mountains, as well as mineral hauyne samples from Germany and Italy. The spectral feature was absent from lapis lazuli samples from California, Chile, Colorado, and New York. Furthermore, poor quality lapis lazuli samples, regardless of locale, highly processed natural pigment samples, and all samples of synthetic ultramarine blue, green, and violet pigments were devoid of encapsulated CO2. [Copyright &y& Elsevier]

Abstract: Afghan lapis lazuli, the source of precious Medieval and Renaissance blue, is known to show a distinctive absorption band in vibrational spectra, which is not present in other natural or artificial ultramarines. Despite the interest of this finding for geochemistry, gemology, history of art and forgery detection, an explanation for these differences has so far been lacking. In this work, we provide evidence based on solid-state NMR spectroscopy together with electronic/vibrational spectroscopy and theoretical models for the occurrence of diamagnetic species HS3 − in the lattice of Afghan lapis lazuli, to which these absorption bands may be attributed. This result, apart from allowing one to authenticate the precious Afghan stone, may help in describing the geochemical origin of lapis lazuli in the different Earth regions. [Copyright &y& Elsevier]

Abstract: In this paper, we describe the main features of the ionoluminescence (IL) apparatus recently installed at the external scanning microbeam facility of the 3MV Tandetron accelerator of the INFN LABEC Laboratory in Firenze. The peculiarity of this IL set-up resides in the fact that the light produced by the ion irradiation of the specimen is collected by a bifurcated optical fiber, so that photons are shunted both to a CCD spectrometer, working in the 200–900nm wavelength range, and to a photomultiplier (PMT). The accurate focusing of the optical system allows high photon collection efficiency and this results in rapid acquisition of luminescence spectra with low ion currents on luminescent materials; simultaneously, luminescence maps with a spatial resolution of 10μm can be acquired through the synchronization of PMT photon detection with the position of the scanning focused ion beam. An optical filter with a narrow passband facing the photomultiplier allows chromatic selectivity of the luminescence centres. The IL apparatus is synergistically integrated into the existing set-up for ion beam analyses (IBA). The upgraded system permits simultaneous IL and PIXE/PIGE/BS measurements. With our integrated system, we have been studying raw lapis lazuli samples of different known origins and precious lapis lazuli artworks of the Collezione Medicea of Museum of Natural History, University of Firenze, aiming at characterising their composition and provenance. [Copyright &y& Elsevier]

Abstract: A new ionoluminescence (IL) apparatus has been successfully installed at the external scanning microbeam facility of the 3 MV Tandetron accelerator of the INFN LABEC in Firenze; the apparatus for photon detection has been fully integrated in the existing ion beam analysis (IBA) set-up, for the simultaneous acquisition of IL and PIXE/PIGE/BS spectra and maps. The potential of the new set-up is illustrated in this paper by some results extracted by the analysis of art objects and advanced semiconductor materials. In particular, the adequacy of the new IBA set-up in the field of cultural heritage is pointed out by the coupled PIXE/IL micro-analysis of a lapis lazuli stone; concerning applications in material science, IL spectra from a N doped diamond sample were acquired and compared with CL analyses to evaluate the relevant sensitivities and the effect of ion damage. [Copyright &y& Elsevier]

Genuine ultramarine has been one of the most precious blue pigments employed since ancient times. It used to be obtained by crushing and grinding the lapis lazuli rock and selectively extracting the blue mineral lazurite. Since 1828, when it was produced the synthetic version, the use of this much less expensive material became widespread and synthetic ultramarine blue replaced the natural one in painting palettes. The distinction between natural and synthetic ultramarine is, therefore, an important goal in authentication issues. Here, we present a hyperspectral microRaman imaging analysis, complemented with the characterization of ultramarine pigment samples in terms of colour, elemental composition and identification of crystalline phases by means of fiber optics reflection spectroscopy (FORS), X-Ray Fluorescence (XRF) and X-Ray diffraction (XRD), respectively. We show that a characteristic luminescence signature, easily detected in the course of standard Raman spectroscopic analysis using 785 nm as excitation, is indicative of the natural origin of the ultramarine blue pigments. Furthermore, simultaneous Raman/luminescence hyperspectral microimages allow the distinction between natural pigments of different quality thanks to the different intensity and spatial distribution of the lazurite characteristic band at 548 cm−1 and those of the luminescent impurities in the region between 1200 and 2000 cm−1. The establishment of a range of quality between different samples of lapis lazuli was also attempted taking into account the variations in the intensity of the Raman bands located at 548 cm−1 and 1286 cm−1. Finally, the feasibility of using the simultaneous Raman/luminescence features for authentication of ultramarine blue in a real historical context, even with non-invasive investigations, is illustrated with examples of different types of blue decorations from several halls of the Alhambra monumental ensemble, in Granada. • Natural ultramarine pigments show characteristic luminescence bands in Raman spectra recorded with 785 nm excitation. • Raman/luminescence hyperspectral micro-images allow quality grading of natural ultramarine pigments. • The use of Raman/luminescence features for authentication of ultramarine blue in a real historical context is demonstrated. [ABSTRACT FROM AUTHOR]

Understanding and building knowledge about color pigments, their history and development have always been a matter of great interest through scientific exploration in the complex system of identification. The characterization of historical works of art is complicated due to the association of several other elements that influence the recorded observations. This entails investigations with multi-analytical techniques to identify the archaeological pigments and confirm their characteristics. The spectroscopic techniques especially Raman spectroscopy and Infrared spectroscopy are very useful for the identification of such materials. In the present communication, the pigments of an historical 18th century wall painting were investigated with micro-Raman spectroscopy, FTIR-ATR & FTIR-KBr, and scanning electron microscopy coupled with energy dispersive x-ray micro-analysis (SEM-EDX). The temple is an exquisite Hindu architecture with valuable artworks still surviving in New Delhi. The results demonstrated the use of red ochre contaminated with carbon for red, yellow ochre for yellow, green ochre for green color and gypsum for the white color in decorations. Lapis lazuli was identified as a pigment for blue probably sourced from Afghanistan through trade on the silk route. The stratigraphy of layers showed the use of lime as a priming layer. FTIR spectroscopy revealed the minor transformation of proteinaceous binding material into calcium oxalate in the paint layer. GC–MS results indicated the possible use of beeswax as a binder for pigments which was further support by FTIR analysis. The analytical data also reveals the trade and resources available in that period. [ABSTRACT FROM AUTHOR]

Abstract: This paper reviews questions around the production of decorated Roman glass vessels with a focus on the enamelling techniques used. A detailed study of beaker fragments from the site of Lubieszewo (type locality for the so-called Lübsow-tombs in Poland) yielded a range of interesting information about glass quality and especially the use of opacifying pigments. It was found by Micro-Raman studies that yellow and white colours were the usual antimony bearing compounds, but red was produced with hematite pigments. Surprisingly, powdered lapis lazuli is responsible for the opaque blue colour. Investigation of the glass medium used for binding the enamel pigments by Micro-X-ray Fluorescence provided indications that beside the yellow lead antimonate, none of the enamel layers contained high lead contents. So the principle of enamelling upon Roman glass seems to be similar to the firing process of short duration observed on Islamic and Venetian enamelled glasses. Analytical results demonstrate that the vessel glass is effectively refined and decolourized by means of antimony. The observations made all testify to the high quality of raw materials used, to the skill of the glass maker(s) and the high rank of the grave owner. [Copyright &y& Elsevier]