Search Results (114)

Studies of prehistoric burials are fundamental for understanding cultural human evolution. Those found in the San Teodoro cave (northeastern Sicily) are significant for the discovery at the turn of the 1930s and 1940s of at least four individuals (ST1–ST4). About 15–16 kyr ago, the bodies of ST1–ST4 were intentionally buried, apparently in a manner original to the context of prehistoric burials, namely by covering them with a continuous layer of red ochre found to connect the graves. Since the earliest excavations, plagued by clandestine digging, there is no material memory of the stratigraphic transition from the burial layer to the subsequent anthropogenic deposit through the red ochre, and nothing certain is known about the orientation of ST3, the presence of grave goods and the ochre cover related to this burial. Moreover, there is no exhaustive knowledge of how much is actually left of the anthropogenic layers described in the old literature. Based on field observations and 3D reconstruction of ST3’s skull position and deposits at the San Teodoro site, we provide insights into anthropological issues, such as the rediscovery of the red ochre vestiges that reasonably covered the ST3 burial, and the burial context of this individual, and shed light on what actually remains of the stratigraphic units described in the 1940s. Full article

This study investigates Hispano-Muslim plasterworks, exemplified by the Cuarto Real de Santo Domingo, the Madraza, and the Alhambra in Granada, focusing on cleaning methods to remove oil-based repaintings without damaging the original polychromies. To this end, samples replicating traditional materials (gypsum coating, pigments, and binders) and techniques (tempera painting) were prepared and subjected to an artificial ageing protocol (AAP). Subsequently, cleaning tests aimed at removing the oil repaintings were performed to recover the original polychromies. Analytical techniques, including Fourier Transform Infrared Spectroscopy (FTIR), Gas Chromatography–Mass Spectrometry (GC–MS), and colorimetry, were employed to evaluate ageing effects and cleaning efficacy. Results revealed significant chromatic alterations in vermilion and azurite bound with animal glue, while ochre remained comparatively stable. Chemical analyses indicated marked binder deterioration, including protein denaturation in animal glue and oxidation/polymerization in linseed oil. Cleaning tests demonstrated that both a heptane–acetone gel and a novel polyamidoamine–glycine (PAAGLY) treatment effectively removed oil-based repaintings while preserving the original layers. These findings highlight the critical role of pigment–binder interactions in conservation strategies and advocate for selective, minimally invasive restoration methods. Full article

Research on fish skin artefacts’ dyeing practices among the Nivkh, Nanai, Ulchi, Udegei, Oroch, and Negidal Indigenous Peoples of the Amur River basin remains scarce. These fishing communities traditionally crafted fish skin garments, essential to their subsistence and spiritual life, adorning them with protective motifs. While artistic and cultural aspects of these belongings have been explored, their dyeing techniques remain understudied. This multidisciplinary research examines natural colourants in fish skin artefacts from international museum collections, using historical textual research, ethnographic records, Native Traditional Knowledge, and previous dye analysis by museum conservators. Findings reveal a restricted but meaningful palette of red, blue, yellow, and black colourants, sourced from plants, minerals, and organic materials. Early dyers extracted blue from indigotin-rich plants such as Polygonum tinctorium, or from Commelina communis petals. Red hues were obtained from Carthamus tinctorius petals, introduced through Silk Route trade networks, or from minerals like red ochre. Black was derived from carbon black, while riverine minerals were ground with dry fish roe diluted with water to create additional colour variations. This study first reviews fish skin use in Amur River Indigenous cultures, explores nineteenth-century dyeing materials and techniques, and finally considers broader implications for Indigenous material heritage. Full article

This paper presents the results of an archaeometric investigation of the preparatory mortars of the pebble pavements of the Basilica of St. Leucio in Canosa di Puglia (Bari, Southern Italy). The main aim of the presented study is to contribute to the dating of some portions of the pebble pavements by analyzing the preparatory layers and determining whether they pertain to the basilica (6^th century CE) or to the pre-existing temple (2^nd century BCE–4^th century CE). Further purposes are to provide information about the production technologies of the mortars and to identify the nature of the pigments found on some pebbles. In order to contribute to the dating studies of the floors, complicated by previous reuse and restoration, 12 samples of mortars, sometimes including pebbles, were collected in different areas of the site. They were analyzed by polarized light microscopy (PLM), X-ray diffractometry (XRPD), X-ray fluorescence spectroscopy (XRF), and scanning electron microscopy coupled with an energy-dispersive spectrometer (SEM-EDS). The results allowed us to advance chronological data on different pavement areas, to deepen our knowledge on mortar production, in terms of both raw materials and technology, and to identify red ochre as the pigment with which the pavement surface was painted. Full article

Loess–palaeosol sequences (LPSs) are continuous records of palaeoenvironmental and palaeoclimatic conditions during the Quaternary. This study includes 17 LPS located in the NE of the Iberian Peninsula, irregularly distributed, associated with different river basins: the Ebro Basin, the Mora Basin, and the Ter sub-basin. The soils developed on these loess deposits present a loam–sandy texture, coarser than the typical loess, ochre in colour, with variable thickness (1–12 m), calcareous composition (20–45% CaCO₃ eq.), very low or null organic matter (OM), and basic pH. These deposits have been classified as desert LPS, whose pedogenesis is mainly associated with the redistribution of calcium carbonate and, in some cases, gypsum. Several methodologies have been applied to determine their mineralogical, physical, and chemical characteristics and date them by luminescence techniques. In addition, some relevant pedofeatures (porosity, CaCO₃, gypsum, etc.) have been characterised in detail. The aims of the present study have been to know the pedogenic development of the LPS by defining the main soil-forming factors that have affected them in order to associate these factors with the characteristic palaeoclimatic and palaeoenvironmental conditions reported in this area over time and to improve the understanding of soil evolution. Full article

The synthesis and symbiotic mechanisms of truffle ectomycorrhizae have attracted considerable scientific interest in recent decades. Although previous research has successfully identified the symbiotic partners of truffles (Tuber spp.) and characterized their mature morphological features, the dynamic processes involved in truffle ectomycorrhizal formation remain insufficiently understood. In this study, we established an ectomycorrhizal synthesis system using Castanea mollissima seedlings inoculated with Tuber sinense spore suspensions under controlled greenhouse conditions, followed by an eight-month observation period. To systematically characterize and model the morphological changes during ectomycorrhizal development, we employed an innovative approach integrating resin sectioning with confocal microscopy. Ectomycorrhizal formation was initially observed two months post inoculation, with a colonization rate reaching 24.4 ± 5.3% by the third month. The ectomycorrhizae displayed a distinct color progression from light brown through ochre and finally dark brown, typically manifesting either monopodial or branched structures. Early developmental stages (2–3 months) were characterized by a thin mycelial membrane enveloping the root surface, accompanied by limited hyphal penetration into the root system. By the eighth month, the colonization rate stabilized at 45.2 ± 8.6%, with enhanced organization and density of the fungal mantle and extended Hartig nets reaching the periphery of outer cortical cells. The continuous growth and differentiation of mycorrhizal root tips generated repetitive root architectures, significantly enhancing symbiotic efficiency. These findings provide critical insights into the morphological development and symbiotic effectiveness of truffle ectomycorrhizae while establishing a methodological framework for investigating ectomycorrhizal associations in other economically significant plant–fungal systems. Full article

The existence of historical pigments databases is important to speed up cultural heritage research. Knowledge of their chemical composition and their manufacture contributes to the study of art history and helps develop accurate conservation-restoration strategies. In this study, a total of nineteen pigments, among which we find silicates (Egyptian blue, natural and synthetic blue ultramarine, green earth and chrysocolla), oxides (natural and synthetic hematite, red and yellow natural ochres, and chromium green), carbonates (natural and synthetic azurite, natural and synthetic malachite, and white lead), sulphides (natural and synthetic cinnabar, and orpiment) and acetates, (verdigris) have been characterized by Fourier Transform Infrared-Spectroscopy in Attenuated Total Reflection (ATR-FTIR) and Diffuse Reflectance (DRIFT) modalities. Considering the latter, there is still a great deal of uncertainty in the interpretation of the different IR vibrational bands. Therefore, a comparative study between these two techniques has been carried out to highlight the potential of DRIFT spectroscopy as a portable and non-destructive technique that allows the differentiation and characterization of historical pigments in the field of cultural heritage. Before performing FTIR analysis, pigments were analysed using X-ray diffraction (XRD) to detect impurities and/or additives in the pigments. Differentiation between natural and synthetic pigments was possible due to the identification of impurities in natural pigments, and manufacture-related compounds or additives in synthetic pigments. Results obtained in this study have proven DRIFT to be a very useful analytical technique for in situ characterization of heritage materials. This study serves as an initial step in clarifying the challenges and uncertainties associated with interpreting spectra obtained through the DRIFT modality. However, the use of other complementary analytical techniques is required. Full article

Multilayer samples are used in a wide range of sectors for their functionality. In the field of cultural heritage, multilayer samples are also common, as in the case of gilded or silvered alloys in the pigment layers in paintings. The X-ray ratios Lα/Lβ, Kα/Kβ, or K/L for an element or for different elements in a multilayer sample depend on the chemical composition and thickness of the superimposed layers and on the chemical composition and thickness of the layer in which the element is situated. Gold decorations of paintings on wood represent examples of multilayered structures and, for this reason, it is important to be able to determine the thickness of the gold layer. In the present paper, gold coatings of several paintings on gilded wood, by Italian artist Taddeo Gaddi (1300–1366 AD), were examined using portable energy-dispersive X-ray fluorescence (ED-XRF) in order to calculate the thickness of the gold layer on ochre by measuring the intensity ratio of the Au-L_α/Fe-K_α X-ray. The experimental results obtained showed that the gold leaves used by the artist have a thickness of approximately 0.3 to 0.4 µm; this also demonstrates the artist’s remarkable ability in creating the gilding. Full article

The Gigantomachy depicted on the west pediment of the Late Archaic temple of Apollo at Delphi marks a significant milestone in early Greek architectural sculpture. Crafted from porous stone and enhanced with plaster and paint, the surviving fragments differ markedly from the marble figures of the east pediment of the same temple. Among the preserved figures of the Gigantomachy are a standing male figure, possibly representing Apollo or Dionysos, a warrior female identified as Athena, and a recumbent male, likely symbolizing the Giant Enkelados. This study aims to investigate the polychromy of the west pediment through a thorough investigation of the remnants of the original decoration. The adopted methodology includes exclusively non-destructive techniques and advanced imaging methods, such as portable X-ray fluorescence spectrometry, visible-induced luminescence (VIL), and 3D microscope observation. Analytical results confirmed the presence of extensive traces of once-vibrant colors on the plaster’s surface, which were often invisible to the naked eye. Specifically, our data support the employment of pigments like Egyptian blue, cinnabar, ochre-based reds and yellows, as well as copper-based green. Notably, these pigments were applied over a white calcium-rich layer, which served as a primer for the porous stone. Ongoing research on the Gigantomachy promises to deepen our understanding of color usage and painting techniques in Archaic Greek art. Full article

This study examines the effects of drying oils—Tung and linseed—on the properties of traditional polychrome coatings applied to wood. Samples prepared with cinnabar, malachite green, yellow ochre, and azurite pigments were analyzed using colorimetric, gloss measurements, surface roughness testing, adhesion strength, and SEM imaging. The results show that Tung oil generally enhances gloss by over 20% and provides superior adhesion, consistently achieving an adhesion grade of 0 (no peeling) across all pigments. Linseed oil, although effective at higher concentrations, displayed more variable adhesion, particularly with blue and yellow pigments. Surface roughness measurements revealed that higher oil content (6:4 ratio) reduced roughness, achieving smoother finishes with Ra values as low as 2.36 μm for Tung oil. SEM analysis confirmed that Tung oil yields a smoother and more even pigment distribution compared to the rougher, clustered morphology in linseed oil samples. These findings underscore the importance of oil type and concentration in achieving desired esthetic and durability outcomes in restoration work. Full article

A technique for characterizing the color of small ochre samples was proposed. The technique includes visual color determination with the aid of a stereomicroscope and a Munsell Soil Color Chart, conversion of Munsell values to CIE L*a*b* coordinates, cluster analysis, and principle component analysis (PCA). The technique was applied to ochre samples from the Kapova Cave and Kamennaya Balka II Upper Paleolithic sites. Characterization of the color of a statistically significant number of pigment samples makes it possible to identify the relationships between different structural features of the cultural layer and reliably identify a wide range of artistic practices in parietal caves in addition to the actual creation of drawings, and it also possibly serves as a chronological marker at multi-layered sites. Full article

Choirbooks are historical heritage manuscripts used for the performance of vocal music in religious ceremonies in colonial times. This study aimed to understand the characteristics of choirbook manuscripts produced in the Real Audiencia de Quito during the 17th century. The methodology combined non-invasive techniques, such as infrared false-color imaging (IRFC) and X-ray fluorescence (XRF), together with spot analysis by scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX) and Fourier transform infrared spectroscopy with attenuated total reflection (FTIR-ATR). The analytical results revealed the use of pumice, chalk and lime carbonate as support materials in the manufacturing process and surface treatment of the parchment. In the illuminations, three pictorial techniques based on protein, polysaccharide and lipid binders were recognized, establishing that the pigments used with greater regularity in the illuminations were vermilion, minium, verdigris, orpiment, azurite, and indigo, preferably in a pure state. Materials used less regularly were also identified, such as yellow ochre, saffron, smalt, red ochre, and bone black, among others. Regarding the vulnerability of the pictorial materials, it was determined that, although most of the pigments exhibit chemical stability, they present some vulnerabilities associated with their intrinsic composition and the medium that contains them. Full article

This research is focused on the laboratory study of salt crystallization inhibitor products as new materials for conservation treatments which can be applied to mortars and painted plasters; as is well known, salt crystallization is one of the most frequent causes of decay processes on decorated architectural surfaces in a wide range of environments. Specifically, the study targets the field of the preventive conservation of mural paintings within rupestrian heritage sites. For the first time, systematic investigations were performed on mock-ups made of plaster painted with two different pigments: yellow ochre and carbon black. Two types of phosphonate inhibitors, PBTC (2-phosphonobutane-1,2,4-tricarboxylic acid) and ATMP (aminotris (methylene phosphonic acid)), were chosen and applied at two different concentrations. Given the limited literature available, and the presence of pigments potentially sensitive to treatment with salt inhibitors, preliminary tests were required. Their effects on the chromatic features of the pigments were evaluated visually and using colorimetry. The changes in the behaviour of water circulation in the mortar resulting from the treatments were evaluated through water vapour permeability and absorption tests. Accelerated crystallization experiments were carried out to assess how inhibitors could influence the growth of salts and the resulting material damage. The latter was carried out by employing sodium sulphate and calcium sulphate solutions, quantifying the damage to the specimens through material loss in weight and the percentage of painted surface loss. Based on the overall results, the product with the best performance was identified was ATMP 0.1% (by volume) in deionized water. The obtained results show that salt inhibitor treatments are promising for in situ application and could represent an innovative approach to promote the sustainable conservation of mural painting, particularly those located in hypogeal contexts, where the salt supply cannot be removed and slowing the growth of salts and/or changing their crystalline habitus may be effective in limiting their damage. Full article

This article offers a discussion of the possibility of distinguishing ochres from Mars pigments. The discussion addresses technological, archaeological, and artistic aspects. Natural earth pigments such as ochres, siennas, and umbers have been widely used from the Paleolithic to the present day and still find wide application despite the development of synthetic iron oxide pigment synthesis processes, called Mars pigments. The potential ability of today’s analytical techniques to distinguish between two classes of pigments of the same color with very similar chemical composition—but perhaps sufficient for reliable recognition—is also discussed. The paper begins by addressing the proper use of the terms “ochres” and “Mars pigments” and their accurate identification in artworks. It reviews the literature on the chemical–mineralogical characterization of yellow and red iron pigments and analyzes pigment catalogs to understand how companies distinguish ochres from Mars pigments. An experimental analysis using External Reflection Infrared Spectroscopy (FTIR-ER) compared painting samples made with natural ochres and Mars pigments, confirming the literature findings and suggesting future research directions. Key differences such as hematite in yellow ochres and specific spectral peaks in red ochres support the potential of FTIR-ER spectroscopy as a noninvasive tool for distinguishing pigments, especially for fragile artifacts and archaeological applications. Full article

This presented research examined the wall paintings in the Church-Ossuary Presentation of the Blessed Virgin, part of the most important Rila Monastery complex in Bulgaria, painted by the painters from Mount Athos in 1795. The painting materials used to create the unique murals were studied for the first time by optical microscopy (OM), attenuated total reflectance Fourier transform infrared (ATR–FTIR), scanning electron microscopy energy dispersive X-ray spectroscopy (SEM–EDS), and enzyme-linked immunosorbent assay (ELISA). The vibrational and elemental analysis showed that the color palette of the paintings is composed of pigments traditional for Orthodox church wall paintings such as natural pigments, including yellow ochre, red ochre, green earth, and calcite, as well as other historical pigments of synthetic origin, including smalt, red lead, cinnabar, and verdigris. The analysis of the binders by the ATR–FTIR spectroscopy and enzyme-linked immunosorbent assay (ELISA) analysis implied the use of the post-Byzantine egg tempera technique. Only the blue backgrounds in the murals were painted using a smalt-based paint mixed with a carbohydrate binder. Based on the current analysis and comparison with the successive paintings in the other churches of the Rila Monastery, it could be concluded that the technology of the painting process followed by the Athonite artists during the work in the Church-Ossuary became a point of reference for many Bulgarian icon-painters later. Full article