Search

A comprehensive understanding of chemical composition of cultural heritage materials usually requires several complementary analytical techniques. Given the fragility and value of artworks, minimizing or avoiding sampling and performing in situ analysis under ambient light is an important goal. This article outlines a novel prototype designed to merge LIBS, laser-induced fluorescence spectroscopy (LIF), Raman spectroscopy using a single pulsed laser, and reflectance spectroscopy in a multi-spectroscopic characterization system for cultural heritage analysis (SYSPECTRAL). The aim is to analyze cultural heritage materials in their original place, obtaining both elemental and molecular information at such same point that is not always insured with several separated experimental settings. The SYSPECTRAL system focuses on compactness, mobility, and ease of operation. Software designed for the prototype controls multi-spectroscopic measurements, allows for image capture, precise localization, and data acquisition. Reflectance spectra examined the material and colors at the surface, and the LIBS-LIF-Raman package examines the stratigraphic structure of a multi-layered painted sample., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

An analytical methodology involving Particle Induced X-ray Emission (PIXE) and Rutherford Backscattering Spectroscopy (RBS) was implemented to respectively characterize the composition and the thickness of silver leaves on gilt leather decors. These objects, ancestors of our wallpapers, are nowadays still difficult to date and their provenance is generally determined from stylistic studies. The initial aim of this study was to identify markers that could be correlated with the object provenance to help distinguishing the different gilt leathers workshops in Europe. The analytical methodology was validated on modern samples and applied to a corpus of 58 ancient gilt leathers from four countries. This study provided an assessment of the sensitivity of the ion beam techniques used, and highlighted the complexity of such analyses on thin silver leaves due to the different factors affecting them, and the composite nature of the object. Thus, the thicknesses calculated from the RBS analyses presented a great variability that seems to be related to the leaf characteristics, the manufacturing process and/or the life of the decor. Nevertheless, observations suggest that silver leaves coming from the Netherlands are thicker than the ones from Spain, Italy or France. Concerning the elemental composition, the results discarded previous hypotheses and the focus was made on gold and mercury trace elements, thus it was shown that leaves in Italian decors seem to have generally a low content of these two elements. Despite the large number of decor analyzed, the corpus should be expanded over to confirm the hypotheses raised by this research. Nevertheless the results gained from this work bring new light on the factors affecting thin metal leaves in general, which will be beneficial to all fields dealing with their analysis., (Copyright © 2019. Published by Elsevier B.V.)

The sophisticated colors of medieval glasses arise from their transition metal (TM) impurities and capture information about ancient glassmaking techniques. Beyond the glass chemical composition, the TM redox is also a key factor in the glass color, but its quantification without any sampling is a challenge. We report a combination of nondestructive and noninvasive quantitative analyses of the chemical composition by particle-induced X-ray emission-particle-induced γ-ray emission mappings and of the color and TM element speciation by optical absorption spectroscopy performed on a red-blue-purple striped glass from the stained glass windows of the Sainte-Chapelle in Paris, France, during its restoration. These particular glass pieces must have been produced as a single shot, which guarantees that the chemical variations reflect the recipe in use in a specific medieval workshop. The quantitative elemental mappings demonstrate that the colored glass parts are derived from the same base glass, to which TMs were deliberately added. Optical absorption spectra reveal the origin of the colors: blue from Co II , red from copper nanoparticles, and purple from Mn III . Furthermore, the derivation of the quantitative redox state of each TM in each color shows that the contents of Fe, Cu, and Mn were adjusted to ensure a reducing glass matrix in the red stripe or a metastable overoxidized glass in the purple stripe. We infer that the agility of the medieval glassmaker allowed him to master the redox kinetics in the glass by rapid shaping and cooling to obtain a snapshot of the thermodynamically unstable glass colors.

A new PIXE setup at the external beamline of the AGLAE accelerator is assessed for fast mapping the joining regions and the PGE inclusions of nine Egyptian gold items from the Louvre museum collection, dated to the end of the 2nd Intermediate Period and to the New Kingdom. The setup is composed of a cluster of SDD detectors divided in two "super detectors" dedicated to analyse the matrix and the trace elements. It provides the possibility to realise large and/or fast maps on artefacts by scanning the beam over the sample surface. Different softwares have been developed or updated to visualise, process, and quantify the data. By using this setup, we could determine the elemental distribution of major elements Au, Ag and Cu on the different joining regions, estimate the composition of the brazes, and show that they were produced by adding Cu to the base gold alloy. By fast mapping the PGE inclusions we could reveal a large variety of compositions within a single object. In addition to the expected Ir-Os-Ru system inclusions, we could also show for several inclusions the presence of another element, Pt. For a region where PGE inclusions overlap the joining area we could show that fast mapping allows to determine the compositions of the inclusion, the brazing alloy, and the base-alloy., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Antique objects are known to have been brightly colored. However, the appearance of these objects has changed over time and paint traces are rarely preserved. The surface of ivory objects (8th century B.C., Syria) from the Louvre museum collection (Paris) have been non-invasively studied by simultaneous particle-induced X-ray emission (PIXE) and Rutherford and elastic backscattering spectrometry (RBS/EBS) micro-imaging at the AGLAE facility (C2RMF, Paris). Qualitative 2D chemical images of elements ranging from Na to Pb on the surface of the ancient ivory carvings provide evidence of lost polychromy and gilding. Quantitative PIXE data of specific areas allow discrimination between traces of sediments and former polychromy. Different shades of blue can be differentiated from particular Pb/Cu ratios. The characterization of gilding based on RBS data demonstrates the exceptional technological skills of the Phoenician craftsmen supposed to have carved the Arslan Tash ivories. More precise reconstructions of the original polychromy compared to previous studies and a criterion for the authentication of ancient gilded ivory object are proposed., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Study of prehistoric art is playing a major role in the knowledge of human evolution. Many scientific methods are involved in this investigation including chemical analysis of pigments present on artefacts or applied to cave walls. In the past decades, the characterization of coloured materials was carried on by taking small samples. This procedure had two main disadvantages: slight but existing damage of the paintings and limitation of the number of samples. Thanks to the advanced development of portable systems, in-situ analysis of pigment in cave can be now undertaken without fear for this fragile Cultural Heritage. For the first time, a portable system combining XRD and XRF was used in an underground and archaeological environment for prehistoric rock art studies. In-situ non-destructive analysis of black prehistoric drawings and determination of their composition and crystalline structure were successfully carried out. Original results on pigments used 13,000 years ago in the cave of Rouffignac (France) were obtained showing the use of two main manganese oxides: pyrolusite and romanechite. The capabilities of the portable XRD-XRF system have been demonstrated for the characterization of pigments as well as for the analysis of rock in a cave environment. This first in-situ experiment combining X-ray diffraction and X-ray fluorescence open up new horizons and can fundamentally change our approach of rock art studies., (Copyright © 2014 Elsevier B.V. All rights reserved.)

A portable X-ray fluorescence/X-ray diffraction (XRF/XRD) system for artwork studies has been designed constructed and tested. It is based on Debye Scherrer XRD in reflection that takes advantage of many recent improvements in the handling of X-rays (polycapillary optics; advanced two-dimensional detection). The apparatus is based on a copper anode air cooled X-ray source, and the XRD analysis is performed on a 5-20 μm thick layer from the object surface. Energy dispersive XRF elemental analysis can be performed at the same point as XRD, giving elemental compositions that support the interpretation of XRD diagrams. XRF and XRD analyses were tested to explore the quality and the limits of the analytical technique. The XRD diagrams are comparable in quality with diagrams obtained with conventional laboratory equipment. The mineral identification of materials in artwork is routinely performed with the portable XRF-XRD system. Examples are given for ceramic glazes containing crystals and for paintings where the determination of pigments is still a challenge for nondestructive analysis. For instance, lead compounds that provide a variety of color pigments can be easily identified as well as a pigment such as lapis lazuli that is difficult to identify by XRF alone. More than 70 works of art have been studied in situ in museums, monuments, etc. In addition to ceramics and paintings, these works include bronzes, manuscripts, etc., which permit improvement in the comprehension of ancient artistic techniques.