Multi-analytical Study Research Articles

A palaeoenvironmental reconstruction of the rampart construction of the medieval ring-fort in Rozprza, Central Poland

During archaeological excavations of a medieval stronghold in Rozprza, a buried thick deposit of deep black (Dark Earth type) soil was discovered. A multianalytical (sedimentological, geochemical and archaeobotanical) study was carried out in order to identify traits the Rozprza Dark Earth. The analyses demonstrated that the soil was formed as an effect of surface accumulation of organic deposits from swampy areas and waste materials with rich admixtures of organic materials. The organic carbon content of the soil of the Rozprza Dark Earth was twice as high, and the total concentration of P was many times higher as compared with the adjacent soil outside the stronghold. Plant macroremains which were recorded within the buried soil and a cultural layer are evidence for human activity, mainly wood gathering and agriculture. In the Early Middle Ages, summer crops could be cultivated there with the use of tilling methods characteristic for root crops or gardens. The accumulation of the Rozprza Dark Earth commenced in the second half of the tenth century AD. In the period between the eleventh and thirteenth century, a ring-fort was established there. The deep black soil is partly covered by the ring-fort’s rampart. The rampart was built with the use of re-deposited earlier cultural layers and sand of the subsoil. It was then clad with sod bricks. Such a construction of a medieval rampart has been recorded for the first time in the territory of Poland. A new interpretation of archaeological structures and cultural layers offers a basis for new conclusions concerning the chronology and the development stages of the medieval settlement and ring-fort in Rozprza.

Multi-analytical study of Roman frescoes from Villa dei Quintili (Rome, Italy)

The present work reports a multi-analytical study, based on Polarized Optical Microscopy (POM), Scanning Electron Microscopy equipped with an Energy Dispersive X-ray detector (SEM-EDX), micro-Raman and Fourier Transform Infrared Spectroscopy (FT-IR) techniques, aimed at establishing the painting techniques and palettes used to decorate a variety of fragments of frescoes coming from Villa dei Quintili in Rome (Italy) and dated back 2nd century CE. This combined methodological approach, covering different spatial scales extending from the macroscopic to the elemental domain, revealed successful for the unambiguous identification and characterization, in non-invasive or at least micro-destructive way, of pigments, binders and stone materials. The used chromatic palette was identified as yellow ochre (goethite), carbon black (vegetal origin), probably green earth and Cu-green pigment, red ochre (haematite), lime white and Egyptian blue (cuprorivaite). Organic and inorganic binders were respectively identified as linseed oil and lime, this latter carbonated to calcium carbonate. Textural features of plasters were also evaluated in order to investigate raw materials used for their production.The obtained data revealed crucial for improving knowledge of materials and preparation methods of pigmenting agents of these fragments, taken from the warehouse of the Villa and hence of unknown provenance area, in view of their right positioning in a specific area of the archaeological complex. In fact, the characterization of the different pigments could support conservators to better identify the distribution of the frescoes among the different rooms, and to reconstruct the original aesthetics of the Villa during the Quintili age.

In-situ multi-analytical characterization of original and decay materials from unique wall mirrors in the House of Gilded Cupids, Pompeii

The House of Gilded Cupids (Regio VI, Insula 16, 7, 38) was unquestionably one of the most important residences of Ancient Pompeii, where important archaeological artefacts such as mural paintings, mosaics, sculptures and lalariums were rediscovered. This work characterizes two wall mirrors that, together with those recovered from the House of Efebo and the Domus of Euplia, represent the only ones found in the archaeological site of Pompeii. The 2015 and 2016 expeditions of the Analytica Pompeiana Universitatis Vasconicae project performed an in situ multi-analytical study, using only portable non-destructive analytical techniques. Molecular data provided by Raman spectroscopy suggested obsidian was the reflective matrix for both mirrors. Elemental data provided by energy dispersive X-ray fluorescence and laser induced breakdown spectroscopy (LIBS) systems were concordant with Raman spectroscopic results, enabling the detection of Ca, K, Al and Na as the main elements included in the Si matrix characteristic of obsidian igneous rocks. The LIBS data confirmed the presence of obsidian hydration layers. All techniques were used to investigate the degraded white and yellow crusts of the mirrors. Gypsum (CaSO4·2H2O) and nitrocalcite (Ca(NO3)2·4H2O) were identified in the white areas and gypsum and goethite (α-FeOOH) in the yellow crusts. LIBS depth profiling on the white crusts found a layer of nitrocalcite on top of the gypsum layer. Gypsum and goethite were proposed to form after partial dissolution of the mortars patches (with high iron contents) used in modern restorations around the mirrors, followed by a reprecipitation on the surface of the mirrors. Nitrocalcite was proposed to form after the attack of atmospheric NOx on gypsum crusts. These results represent the first analytical work focused on the study of these unique mirrors and provide the knowledge needed for defining more adequate conservation treatments.

Discovery and multi-analytical study of the last missing quarter from Ren\xe9 Magritte\u2019s La pose enchant\xe9e

The last missing quarter of La pose enchantée, a 1927 Magritte’s oil painting disappeared in 1932, has been finally found beneath Dieu n’est pas un saint, picture painted by the Belgian surrealist between 1935 and 1936, conserved at the Brussels Magritte Museum (Royal Museums of Fine Arts of Belgium) (inv. 11681). The in-depth study conducted on Dieu n’est pas un saint by means of non-invasive and complementary imaging and analytical techniques has allowed formulating substantiated conclusions regarding this double painting. On the one hand, the routine imaging methods, including XRR, IRR and digital microscopy, have delivered a comprehensive outcome regarding the transformation process of the right top part of La pose enchantée into the current composition. On the other hand, the pigments used for both the visible and the hidden composition have been characterized through the MA-XRF analysis of the whole picture and punctual Raman measurements. Additionally, the present paper proposes a virtual colorization of La pose enchantée, which has been build on the basis of the overall material evidences collected about the right top part lying beneath Dieu n’est pas un saint.

The Elamite metalworkers: multianalytical study on copper objects and ingots from second millennium BC of southwestern Iran

An analytical study was performed on copper alloy objects and ingots/prills from Haft Tappeh Middle Elamite site, southwestern Iran, fourteenth century BC. The samples were analysed by micro-PIXE and SEM-EDS methods to characterise chemical composition and different phases in their microstructure. The results showed that the main objects’ compositions are copper with impurities and variable-Sn containing tin bronze. Furthermore, most of the ingots/prills are composed of copper with high concentration of iron and sulphur while in two samples tin bronze ingot/prill is detected. Based on the results, the main metallurgical operation in Haft Tappeh may be matte production to make metallic copper and producing tin bronze alloy probably by cementation.

A multi-analytical study on the Mango Longo Guitar, a Baroque masterpiece from the Castello Sforzesco, Milan, Italy

Abstract The study of an ancient musical instrument should take into account various approaches, which include historical sources, study of materials and dendrochronological analysis. Very often, an ancient musical instrument has been subject to repairs, substitutions and restorations that have modified its original setting. This study takes into account the “Mango Longo guitar”, a masterpiece of 17th century Neapolitan art. It has been analysed from a historical, organological and xylo-chronological perspective to investigate and describe the cultural context of its creation, the wood species used for its construction and various restoration works to which it has been subjected. The Mango Longo guitar belongs to the typology of the Baroque guitars of the seventeenth century, attributed to the lute-maker of German origin Magnus Lang, from which the name derives. The most recent tree-ring identified on the instrument belly is dated dendrochronologically to 1737, terminus post quem. This means that the actual soundboard may be considered a replacement, due to a restoration in the first half of 18th century. The analysis of dendroprovenance of the actual soundboard shows strong analogies with Italian production of the period and identifies the probable sources for wood as being in the Alps. Our results confirm the intensive and well-organized trade of valuable timber used for musical instruments at that time.

New insights into the composition of Indian yellow and its use in a Rajasthani wall painting

The widespread occurrence of Indian yellow on an early 17th-century wall painting in Rajasthan (India) was initially indicated by photo-induced luminescence imaging of the painted scheme in the Badal Mahal within the Garh Palace (Bundi). The presence of the organic pigment was subsequently confirmed by HPLC-ESI-Q-ToF. The results of a multi-analytical study focusing on two samples from the wall painting and two reference pigments from the British Museum and National Gallery (London, UK) are presented here. The research focused on the possible causes for the different yellow/orange hues observed in the painting samples.Analysis of cross-sections with SEM-EDS revealed similar elemental composition for the Indian yellow paint layers, but different underlying layers, indicating a variation in painting technique. The composition of the Indian yellow samples was investigated by HPLC-ESI-Q-ToF with both positive and negative ionisation. In addition to euxanthic acid and euxanthone, a sulphonate derivative of euxanthone was found to be present in all samples, while relative amounts of the three components varied. Flavonoid molecules—morin, kaempferol, quercetin and luteolin—were also detected in one wall painting sample (characterised by a brighter yellow colour) and not in the sample that was more orange.The optical properties of the samples were characterised by photoluminescence spectroscopy in both solid state and aqueous solution. The contribution of each organic compound to the emission spectrum of Indian yellow in solution was also investigated by time-dependent density functional theory (TDDFT) calculations. Small differences in terms of spectral shift were observed in solid state experiments, but not in solution, suggesting that the spectral differences in the emission spectrum were mostly due to different contributions of solid-state arrangements, most likely driven by π-π stacking and/or hydrogen bonds. However, a slight difference at high energies was observed in the spectra acquired in solution and TDDFT calculations permitted this to be ascribed to the different chemical composition of the samples. Time-resolved measurements highlighted di-exponential lifetime decays, confirming the presence of at least two molecular arrangements. Py(HMDS)-GC–MS was also used for the first time to characterise Indian yellow and the trimethylsilyl derivative of euxanthone was identified in the pyrograms, demonstrating it to be a suitable marker for the identification of the pigment in complex historic samples.

Gothic green glazed tile from Malbork Castle: multi-analytical study

Looking at the façade of a historical building, it is often difficult to distinguish between the original decoration and later additions. One such building is the Holy Virgin Mary Church at the Malbork Castle (Northern Poland), built between 1276 and 1406. During the latest restoration works, ceramic tiles with some remnants of the green glaze, decorating the Holy Virgin Mary Church façade, were studied in situ using portable X-ray fluorescence spectrometry. Micro-samples were analyzed in laboratory by scanning electron microscopy with energy dispersive X-ray spectrometry (SEM–EDS) and wavelength-dispersive X-ray spectrometry (SEM–WDS), micro-Raman spectroscopy and powder X-ray micro-diffraction. We found that what was originally thought to be a paint layer was in fact a heavily deteriorated SiO2–PbO glaze. White, yellow and black pigments were found to have been added into the glaze as opacifiers and colorants. Copper and iron were used as glaze colorants. The originally added pigments were transformed into new phases, such as antimony-doped tin oxide. The technology used to produce the glazed tiles was identified. All the results collectively confirmed the medieval origin of the green glazed tiles.Graphical abstractGothic green glazed tile from Malbork Castle: multi-analytical study.

Multianalytical study of corrosion layers in some archaeological copper alloy artefacts

Corrosion layers in some copper and bronze archaeological objects from Haft Tappeh archaeological site, southwest Iran, were studied. For this purpose, optical microscopy, scanning electron microscopy with energy dispersive X-ray microanalysis, micro-Raman spectroscopy and X-ray diffraction methods were applied to observe corrosion stratigraphy and their characteristics as well as identification of chemical composition and phase determination of different corrosion layers. Based on optical and electron microscopy, three different corrosion strata were identified in cross section of different metallic objects including various red, green, white-grey powdery and dark internal compact layers. Scanning electron microscopy with energy dispersive X-ray microanalysis on different corrosion layers revealed that Cu, Sn and Cl are the main elements in the chemical composition of different layers. Tin-rich phases were detected in white-grey and dark layers that may be formed because of the internal oxidation of tin as well as the decuprification (selective dissolution of copper) phenomena occurring during long-term burial period in the soil. Also, the XRD and micro-Raman spectroscopy results proved that the main corrosion products are nantokite (CuCl), copper trihydroxychlorides and copper oxides. The combination of these analytical methods allows us to explore the surface and internal corrosion layers of the archaeological copper and bronze samples, and major interest is on studying their chemistry, microstructural properties and corrosion stratigraphy. Copyright © 2015 John Wiley & Sons, Ltd.

A multi-analytical study of the Belarusian icon “Virgin Eleusa” (XVII cent.)

Abstract Here the results are reported on the multi-analytical study of the Belarusian icon “Virgin Eleusa” (XVII cent.). The X-ray and luminescence studies revealed some interventions performed in different time periods. The materials of original painting as well as the materials of interventions were successfully characterized by spectroscopic techniques. Layer-by-layer Laser induced breakdown spectroscopy (LIBS) was used for elemental composition study of art materials. Fourier-transform infrared microspectroscopy (micro-FTIR) was used to indicate the types of binding media in the grounds and paint layers as well as to identify the art pigments. A low concentration of cerulean and cadmium yellow in the upper paint layers (interventions) were identified by Surface enhanced Raman scattering (SERS). Since cerulean and cadmium yellow are known to come into use in XIX cent., the SERS results played the crucial role for dating of some intervention.

Multi-analytical study of ceramic pigments application in the study of Iron Age decorated pottery from SW Iberia

A non-invasive multi-analytical approach combining optical microscopy (OM), micro-X-ray diffraction (µXRD), in-situ X-ray fluorescence spectroscopy (XRF), variable pressure scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (VP-SEM-EDS) and Raman micro-spectroscopy has been employed for the first time to investigate the chemical composition of ceramic pigments in Iberian Iron Age ceramics. The methodology was applied in the study of red, black and white pigments on Iron Age decorated pottery from the archaeological site of Garvão (SW Portugal). The complementary methodology adopted in this study minimized the damage to the ancient artefacts and turned out to be essential in achieving a complete chemical and mineralogical characterization of pigment composition.Results suggest that haematite (Fe2O3) and pyrolusite (MnO2) are the main mineral carriers of the Fe and Mn chromophore ions, responsible respectively for the red and black colour. While illite (K(Al,Mg,Fe)2(Si,Al)4O10(OH)2), a common clay mineral, is giving the white colour. It is the first time that the use of illite as a pigment on decorations of ancient pottery has been reported in western societies.The potters used local raw materials, compatible with the regional geological context and the archaeometric study seems to demonstrate that the society that produced the painted ceramics had limited access to long commercial routes.

The decay of the polysiloxane resin Sogesil XR893 applied in the past century for consolidating monumental marble surfaces

Abstract A study of the deterioration micromorphologies and a chemical investigation of the alteration products of an experimental polysiloxane resin used for consolidating marble sculptures in Venice was undertaken several decades after the initial treatments. A multianalytical study was carried out on a number of microfragments sampled from four Venetian monuments treated in the 1960s and ‘70s. The Fourier Transform InfraRed spectroscopic analysis (FTIR and μFTIR) was used to identify the conservative treatment applied, to confirm its chemical nature (whose formulation has never been confirmed) by comparing the results with the literature, and to investigate both its behaviour under a very aggressive environment and the possible related deterioration products. Microscopic observations of cross-sectioned samples (mainly through SEM-EDX analysis) were conducted to investigate the resin morphology and distribution into the pores, and to identify the possible residual presence of other conservative products previously or subsequently applied. In addition, water absorption by means of the sponge contact method was used to verify the present water repellency of the treated surfaces. The methodology adopted proved to be adequate to the aim of the research and gave useful information about the performance of the resin examined over time.

Bronze alloy production during the Iron Age of Luristan: a multianalytical study on recently discovered bronze objects

Application of bronze alloy to produce artistic and religious artefacts was commonplace during the Iron Age in western Iran (1500–550 BC). These bronze artefacts are the so-called Luristan bronzes and have been found often from excavated graves and sanctuaries. The aim of this paper is to study on alloy composition and manufacturing process in some recently excavated objects from the Iron Age cemetery of Baba Jilan, northern Luristan. For this purpose, some objects were analysed by quantitative ICP-MS as well as microscopic studies by scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM-EDS) and metallography methods. Also, some comparisons were carried out between Baba Jilan and other analysed bronze objects from Luristan in order to identify the metalworking process in bronze objects from the Iron Age of western Iran. The results showed that all Baba Jilan samples are made of binary copper-tin alloy. Tin content was variable in the composition of the samples. The variety of tin constituents proved that alloying has been performed by an uncontrolled process to produce bronze. The microscopic studies also showed that the manufacturing operations are similar in the Luristan bronzes. It was carried out to identify probable similarities in the bronze alloy production in the Iron Age of the Luristan region.

Multi-method Analysis of Avian Eggs as Grave Goods: Revealing Symbolism in Conversion Period Burials at Kukruse, NE Estonia

ABSTRACTEggshells are unusual finds in the Iron Age of eastern Europe (500 BC–1200 AD) deserving extra attention in terms of analysis as well as interpretation. This paper discusses two rare eggshell finds, discovered in female burials at the conversion period (12th–13th century AD) cemetery at Kukruse, NE Estonia. Our multianalytical study combining FT-IR, SEM(-EDS), microscopy and ZooMS provides an overview of methods applicable for identifying egg species, their predepositional history and curation. Based on the analytical results and the comparative analysis of the content and context of these two burials, we argue that different aims and connotations lay behind depositing eggs as burial goods, allowing well-supported interpretations of both pagan and Christian religious worldviews simultaneously.

Multi analytical technique study of human bones from an archaeological discovery

In 1953, during the building restoration of San Michele church (Bono, Sardinia, 16th–19th Century), a high number of disarticulated skeletons were recovered. From a group of 412 hip bones, two of these, affected by several pathological lesions, were analysed. The two coxal bones can be referred to the same individual, an adult man. A multi-analytical study, started with the purpose of investigating the bone pathology, was extended to characterize the mineral components of a large representative set of bones from the same ossuary, all attributed to adult men who lived in the region four-two centuries ago. A quantitative ICP-AES analysis for Ca, Fe, Mg, Mn, Na, Pb and Zn was executed, and a chemometric investigation on the results was performed. This approach gave evidence of the effects of diagenesis, allowed some hypothesis of the incidence of the known dietary habits on bone composition, and completely differentiated the pathological bones from those of a normal population on the basis of the mineral composition. Moreover, porosity, crystallinity and FT-IR analysis were conducted on both non- and pathological sample.

Multi-analytical study of the suspected binding medium residues of wall paintings excavated in Tang tomb, China

Abstract The analysis of the organic binding media in the field of cultural relics is invariably challenging due to the micro-amount, complex ingredients and degradation problems. Black residues of suspected binding media were discovered in a tomb archaeological site of the Tang dynasty (618-907AD), one of the most prosperous time in the ancient China. In the frame of excavation campaign it is becoming a demand to analyze the precious archaeological samples to know more about the composition of these materials. In this paper, efforts were made to analyze this sample with Fourier Transform Infrared Spectroscopy (FTIR) and Gas Chromatography (GC), attempting to learn the materials’ consistence. This study would enrich the research of the materials of mural paintings in the Tang dynasty as well as providing a scientific basis for the future restoration.

Multianalytical Study of the Binding between a Small Chiral Molecule and a DNA Aptamer: Evidence for Asymmetric Steric Effect upon 3'- versus 5'-End Sequence Modification.

Nucleic acid aptamers are involved in a broad field of applications ranging from therapeutics to analytics. Deciphering the binding mechanisms between aptamers and small ligands is therefore crucial to improve and optimize existing applications and to develop new ones. Particularly interesting is the enantiospecific binding mechanism involving small molecules with nonprestructured aptamers. One archetypal example is the chiral binding between l-tyrosinamide and its 49-mer aptamer for which neither structural nor mechanistic information is available. In the present work, we have taken advantage of a multiple analytical characterization strategy (i.e., using electroanalytical techniques such as kinetic rotating droplet electrochemistry, fluorescence polarization, isothermal titration calorimetry, and quartz crystal microbalance) for interpreting the nature of binding process. Screening of the binding thermodynamics and kinetics with a wide range of aptamer sequences revealed the lack of symmetry between the two ends of the 23-mer minimal binding sequence, showing an unprecedented influence of the 5' aptamer modification on the bimolecular binding rate constant kon and no significant effect on the dissociation rate constant koff. The results we have obtained lead us to conclude that the enantiospecific binding reaction occurs through an induced-fit mechanism, wherein the ligand promotes a primary nucleation binding step near the 5'-end of the aptamer followed by a directional folding of the aptamer around its target from 5'-end to 3'-end. Functionalization of the 5'-end position by a chemical label, a polydA tail, a protein, or a surface influences the kinetic/thermodynamic constants up to 2 orders of magnitude in the extreme case of a surface immobilized aptamer, while significantly weaker effect is observed for a 3'-end modification. The reason is that steric hindrance must be overcome to nucleate the binding complex in the presence of a modification near the nucleation site.

The short-term degradation of cellulosic pulp in lake water and peat soil: A multi-analytical study from the micro to the molecular level

Cellulosic pulp was analysed after two and five years of natural ageing in two different burial environments - lake water and peat soil - in order to investigate the chemical and structural changes undergone by the material. This research is part of a monitoring program developed in the archaeological site of Biskupin, whose final aim is to estimate the best re-burial conditions for an in situ conservation of archaeological wood. We applied SEM, FT-IR, XRD and Py-GC/MS with thermally assisted silylation using hexamethyldisilazane (HMDS) to obtain broad information on cellulosic pulp degradation.SEM provided information on the structural changes undergone by the fibres and on the microbial activity. FT-IR highlighted a depletion of the carbohydrates in the most degraded samples. Py(HMDS)-GC/MS confirmed these observations and provided detailed molecular information on cellulose alteration. The crystallinity index (CI) of cellulose was estimated by XRD, showing that the degradation began in amorphous regions. The correlation between the CI and the relative abundance of anhydrosugars detected by Py(HMDS)-GC/MS demonstrated that pyrolytic reactions are also influenced by the degree of crystallinity of cellulose.A mechanism of cellulose degradation in these natural environments was formulated: the degradation of cellulose in these natural environments proceeds through a depolymerisation step, initially involving the amorphous regions of cellulose, until the size of oligomers becomes sufficiently small to allow metabolisation by microorganisms or solubilisation by water. Secondly, a loss of carbohydrates was detected after five years of ageing and the loss reached 25% and 55% for the dark areas of samples aged in peat soil and lake water, respectively. Peat soil was found to be more suitable than lake water in terms of preservation of carbohydrates.

A multianalytical study of oil binding media and pigments on Bohemian Panel Paintings from the first half of the 14th century

Abstract This paper deals with the results of a broad-based survey of both the binding media and the pigments used during the first half of the 14th century on Bohemian panel paintings from the collections of the National Gallery in Prague. The work is focused on the specific use of oil binding media and pigments in the workshop of the Master of the Vyssi Brod Cycle, the most important painter in the period around the 1340s in Bohemia. Extensive laboratory examinations of the micro-samples were executed by means of optical microscopy (OM), scanning electron microscopy with an energy-dispersing detector (SEM/EDS), micro-Raman spectroscopy (MRS), histochemical staining (HS) and gas chromatography/mass spectrometry (GC/MS). The data obtained by the multianalytical approach pointed out that the oil binding medium was used as the principal medium within colour paint layers in the Bohemian panel paintings as early as around 1340–1350. This unique identification of oil binding media opens new possibilities for the interpretation of the painting technique in Central Europe in the 14th century.

Spectroscopic pigment identification in ornamentation tiles (XIII - XV ac) from Aveh, Qom and Masshad in Iran

In this work the Raman spectroscopy and complementary techniques are used to identify and compare pigment components in the ornamentation tiles excavated in archaeological sites of Aveh, Qom, and Masshad in Iran, which are dated for XIII – XV c. Results indicate on use of different blue pigments for production of tiles found in sites distanced by ca 100km, the usage of Fe oxide based ochre and red pigments in mixtures and confirm advanced luster technique with Pb-rich oxides and traces of corroded Ag. Full Text: PDF References J. Perez-Arantegui et al., "Materials and technological evolution of ancient cobalt-blue-decorated ceramics: Pigments and work patterns in tin-glazed objects from Aragon (Spain) from the 15th to the 18th century AD", J. Eur. Ceram. Soc. 29, 2499 (2009). CrossRef S. Coentro et al., "The Colors and Techniques of 17th Century Portuguese Azulejos: a Multi-Analytical Study", Microscopic Microanal. 17, 1782 (2011). CrossRef S. Gulzar et al., "Characterization of 17th Century Mughal tile glazes from Shahdara Complex, Lahore-Pakistan", J. Cult. Herit. 14, 174 (2013). CrossRef L. Kock, et al., "Raman analysis of ancient pigments on a tile from the Citadel of Algiers", Spectrochim. Acta A 4 1348(2008). CrossRef http://rruff.info/. DirectLink R. Clark, M. Curri, "The identification by Raman microscopy and X-ray diffraction of iron-oxide pigments and of the red pigments found on Italian pottery fragments", J. Mol. Struct. 440, 105 (1998). CrossRef I. Żmuda-Trzebiatowska et al., "Raman spectroscopic signatures of the yellow and ochre paints from artist palette of J. Matejko (1838–1893)", Spectrochim. Acta A 136, 793 (2015). CrossRef