SCIENTIFIC ANALYSIS OF SEVENTH‐CENTURY GLASS FRAGMENTS FROM THE CRYPTA BALBI IN ROME*

Inductively coupled plasma emission spectroscopy, reflectance spectroscopy and X‐ray diffraction were used to study seventh‐century AD glass fragments from the Crypta Balbi in Rome. All the samples were found to be silica‐soda‐lime glasses. Iron determines the colour of blue‐green, green and yellow‐green transparent glasses; chemical composition suggests deliberate addition of iron and/or manganese in about half the samples. Copper was found as the main colourant in red, pale blue and blue‐green opaque fragments; elemental copper acts as an opacifier in red glass, and calcium antimonate in white, pale blue and blue‐green glasses. Detection of antimony in transparent fragments suggests recycling of opaque mosaic tesserae.     

The Characterization of Vegetable Tannins and Colouring Agents in Ancient Egyptian Leather from the Collection of the Metropolitan Museum of Art

This work characterizes both tanning and colouring materials found in ancient Egyptian leather objects from the Metropolitan Museum of Art. The analytical investigations focused on assessing the development of the technology of ancient tanners using high‐performance liquid chromatography (HPLC), surface‐enhanced Raman spectroscopy (SERS), X‐ray fluorescence (XRF), Fourier transform infrared spectroscopy (FT–IR), X‐ray radiography and a scanning electron microscope connected to an energy‐dispersive X‐ray detector (SEM–EDX). Reference leather samples and archaeological leather objects were investigated to identify the animal skin species and the early use of hydrolyzable vegetable tannins for leather tanning. Different methods were used to colour th leather, including madder dying and staining with hematite, or painting with Egyptian blue and Egyptian green.     

The Structure and Chemical Composition of Wall Paintings From Islamic and Christian Times in the Seville Alcazar

Wall paintings from the Islamic epoch (10th to 12th centuries) and the Christian monarchy (14th to 16th centuries) have been recovered in discarded materials and on walls after reconstruction works in the Seville Alcazar. These paintings have spent centuries underground or under a plaster coat. Portable X‐ray fluorescence (XRF) and combined XRF/X‐ray diffraction (XRD) were employed in situ, as well as scanning electron microscopy (SEM–EDX), grazing angle incidence XRD and micro‐Raman spectroscopy, on cross‐section samples to fully characterize the materials in the wall paintings. Using these methods, the fresco technique was demonstrated, and many kinds of pigments were identified in accordance with the various periods of the history of the Alcazar, thus assessing the authenticity of all the wall paintings studied here.     

Physico‐Chemical Characterization of Pigments and Binders of Murals in a Church in Ethiopia

Here, we report the physico‐chemical characterization of wall paintings from the Petros and Paulos church in Ethiopia. This work represents the first technical study of paintings located in Ethiopia, rather than paintings in museum collections outside the country, using diverse analytical techniques. In situ examination with a portable X‐ray fluorescence spectrometer (pXRF) was followed by analysis of samples using optical microscopy (OM), scanning electron microscopy coupled with energy‐dispersive X‐ray spectroscopy (SEM/EDS), micro‐Raman spectroscopy (MRS), attenuated total reflection – Fourier transform infrared spectroscopy (ATR‐FT–IR), X‐ray powder diffraction (XRD) and pyrolysis gas chromatography – mass spectrometry (Py‐GC/MS). The paint stratigraphy, the compositions of the support material, the preparatory and painting layers were studied, as well as the morphology of the pigment particles. The results revealed the use of earth pigments and carbon black. The preparatory layer was uncommon; composed of dolomite, clay rich in clinochlore and sand, in contrast to the more common gypsum and calcite. The binder and the stratigraphic analyses suggested a distempera technique.     

Black Gloss Pottery: Production Sites and Technology in Northern Etruria,Part II: Gloss Technology

The present study aims to understand the reasons for the visual differences of black gloss pottery found in northern Etruria. The results obtained by conventional (scanning electron microscope, electron microprobe) and synchrotron (X‐ray diffraction, X‐ray absorption spectroscopy) techniques indicate that the thickness, porosity or chemical composition of the different types of gloss cannot be used as the principal distinguishing factor. The size of quartz or feldspar crystals may well be a critical factor responsible for the matt effect in some samples, while the range of mixtures of iron compounds indicated by XRD and XAS could be the reason for differences in colour and reflectivity. The Fe L‐edge XAS results in particular show that a correlation does exist between the oxidation state characteristics and the visual appearance. The Si, Fe and Al contents seem to further discriminate the different types of gloss that have differing visual appearances.     

RESEARCH ON THE PIGMENTS FROM PAINTED CERAMICS EXCAVATED FROM THE YANGQIAOPAN TOMBS OF THE LATE HAN DYNASTY (48 BC – AD 25)

The analysis of pigments on painted ceramics excavated from the Yangqiaopan Tombs of the late Western Han Dynasty was undertaken using optical microscopy (OM), micro‐Raman spectroscopy (μ‐RS), scanning electron microscopy with energy‐dispersive X‐ray spectrometry (SEM–EDS), X‐ray diffraction (XRD) and Fourier‐transform infrared spectroscopy spectra (FTIR). The pigments were identified as red lead (Pb₃O₄), carbon (C), malachite [Cu₂CO₃(OH)₂], Chinese purple (BaCuSi₂O₆) and illite {[K,H₃O]Al₂Si₃AlO₁₀(OH)₂}. Fibrous materials were observed in some pigment samples. When observed by SEM, one showed a large amount of fibre in solidified gum, which indicated that gum of ramie could have been used as the binding medium to make the pigment particles adhere together. These results provide significant insights into the characteristics of these pigments in the Qin and Han Dynasties.     

CHARACTERIZATION OF PLASTERS FROM PTOLEMAIC BATHS: NEW EXCAVATIONS NEAR THE KARNAK TEMPLE COMPLEX,UPPER EGYPT*

The aim of the present work is to characterize plasters from Ptolemaic baths recently discovered in front of the Karnak temple complex, by the excavations of an Egyptian–French team. The characterization was carried out by means of optical microscopy (OM), scanning electron microscopy (SEM) equipped with an energy‐dispersive X‐ray detector (EDS), X‐ray diffraction analysis (XRD) and Fourier transform infrared spectroscopy (FT–IR). The results allowed the identification of the chemical composition and structure of these plasters. In addition, samples of red, yellow, black and white pigments were examined and identified. The results helped in providing an image concerning some materials used during the Ptolemaic era in ancient Egypt.     

X‐ray Diffraction and SEM Investigation of Wall Paintings Found in the Roman Temple Complex at Horvat Omrit,Israel

In the present study, the fragments of wall painting found in the Roman Temple Complex at Horvat Omrit were analysed for the first time using the non‐destructive techniques of X‐ray diffraction (XRD) and scanning electron microscopy (ESEM) equipped with energy‐dispersive X‐ray spectroscopy (EDS). The application of these methods enabled unambiguous identifications of the pigments and plaster components of the samples. Quantitative information on mineral composition, crystallite size and elemental composition of each studied paint layer and plaster was collected. Based on the results of the XRD and EDS analyses, the green pigment was identified as celadonite. It was revealed that the Egyptian blue pigment does not contain impurities of tin and lead, and this excludes the use of bronze scrap in its synthesis. Comparison of the mineral composition of the paint layers indicates that a wider palette of colours was obtained by mixing the available mineral pigments. The study of cross‐sections of painted specimens revealed the usage of slaked lime for plastering. The obtained results give a new insight into the wall painting technique employed by ancient artists at Horvat Omrit, in northern Israel.     

道教人物画像颜料的原位无损分析

利用漫反射光谱、显微激光拉曼光谱和能量色散X射线荧光技术,对一张道教人物画像的颜料进行原位无损鉴别,结果显示,画像主要使用了朱砂、巴黎绿、群青、雌黄、碳黑和铅白。为了明确群青是人工合成还是天然颜料,采用X射线衍射对画像蓝色颜料进行物相分析,结果表明,该颜料确为合成群青。由于群青和巴黎绿均为人工合成颜料,其首次合成时间分别为1828年和1814年,清代晚期引入我国,由此推断该画像应在清代晚期以后绘制。这一研究表明,上述三项技术联用非常适合于易损和不允许取样的古字画颜料的无损分析鉴定,在纸张类文物分析中具有广阔的应用前景。     

The Application of Scanning X‐ray Fluorescence Microanalysis in the Examination of Cultural Materials

The use of a new analytical technique for the elemental characterization of artefacts is described. The new equipment is capable of X‐ray fluorescence analysis in conventional mode as well as for elemental scanning of small objects, fragments or microsamples. The Omicron, manufactured by Kevex Instruments Inc., is equipped with a microfocused X‐ray tube, which can be collimated to a 50 μ beam and used to scan objects over a maximum range of 256 × 256 pixels. False‐colour elemental distribution maps allow the user to image small features, differently pigmented areas, or whole objects in the machine completely non‐destructively. Analyses can be carried out in air, under helium or in vacuum. Two examples of the application of the new technique are described: first, to the surface decoration on a Greek Attic white ground lekythos; and, second, to the pigments used on a small painting, a ‘Pittura’, on copper by the Dutch artist, Frans van Mieris (1635–81) in the collections of the J. Paul Getty Museum.     

DOMUS AUREA,THE ‘SALA DELLE MASCHERE’: CHEMICAL AND SPECTROSCOPIC INVESTIGATIONS ON THE FRESCO PAINTINGS

In this paper, data collected from the wall fresco paintings of room 114, called the ‘Sala delle maschere’, of the Domus Aurea in Rome is analysed. The chemical composition of the efflorescence is investigated by infrared spectroscopy. The colour palette is determined by means of EDXRF, Raman spectroscopy and visible reflectance spectroscopy. EDXRF has allowed an extensive mapping of the elements present in the pigments and plaster; whilst in‐situ Raman spectroscopy has been determinant for attributing the molecular composition of the pigments in a number of doubtful cases. Most pigments identified are typical of Imperial Roman fresco paintings (first to fourth centuries AD) ( Ward‐Perkins 1981 ); more interestingly, we found evidence of fragments painted with Egyptian blue, which was normally used mostly in official rooms.     

The production and technology of glazed ceramics from the middle ages,found in the saepinum territory (Italy): a multimethodic approach*

A collection of ceramics from the Middle Ages found in Altilia and Terravecchia (the Saepinum area, Campobasso, Italy) were characterized by using different mineralogical analyses to investigate their provenance and production techniques. The body ceramic was investigated using Rietveld phase analysis of X‐ray powder diffraction patterns, X‐ray fluorescence spectrometry and scanning electron microscopy. The chemical compositions of the coatings were measured by scanning electron microscopy and their mineralogical compositions were determined using a particular technique of X‐ray small‐angle scattering (SAS) optimized for studies of thin films. Moreover, the material used for decoration was studied using micro‐Raman spectroscopy. The archaeometric results confirmed the distinction into two different ceramic classes, already individuated from archaeological analysis: the Altilia objects belong to the protomajolica class, whereas the objects from Terravecchia are RMR (ramina‐manganese‐red) ceramics. A comparison between the chemical and mineralogical compositions of good‐quality ceramic objects and those of waste products indicated local production of the ceramics. A sharp distinction was found in the chemical composition of the coatings: the Altilia products have tin‐opacified lead glazes, while the Terravecchia ones have transparent high‐lead glazes. Among the Altilia products, the unsuccessful process that produced a large quantity of discarded materials was attributed to the high lead content of the glazes. In fact, the principal advantage of the high lead content was to make the preparation and application of the glaze suspension easier, but the risk of reduction of lead oxide to metallic lead was greatly increased. Using micro‐Raman spectroscopy, the following minerals were identified as pigments: pyrolusite for the dark colour, malachite for green, lepidocrocite for yellow and hematite for red.     

THE CHARACTERIZATION OF PAINTS AND WATERPROOFING MATERIALS FROM THE SHIPWRECKS FOUND AT THE ARCHAEOLOGICAL SITE OF THE ETRUSCAN AND ROMAN HARBOUR OF PISA (ITALY)*

This work presents the results of a diagnostic survey on the shipwrecks from the archaeological site of the ancient harbour of San Rossore (Pisa, Italy). The original waterproofing, caulking and painting materials were characterized by Fourier transform infrared spectroscopy (FTIR), gas chromatography – mass spectrometry (GC–MS), energy‐dispersive X‐ray microanalysis (EDX) and X‐ray diffraction (XRD). The major constituents of the waterproofing and caulking materials detected on the planks were tricyclic abietanes showing a high degree of aromatization. These compounds are indicative of a pitch obtained from the wood of trees of the Pinaceae family. The analysis of the organic components of the paint samples revealed diterpenoid acids characteristic of Pinaceae resins together with linear long‐chain alcohols and fatty acids, highlighting the presence of beeswax. Noticeably, the characteristic odd carbon number alkanes that are normally present in beeswax were not detected. The EDX and XRD analyses showed that hematite, calcite, cerussite and kaolinite were employed as pigments to paint the ships’ hulls.     

MULTIANALYTICAL STUDY OF PALAEOLITHIC REINDEER ANTLER. DISCOVERY OF ANTLER TRACES IN LASCAUX PIGMENTS BY TEM*

Palaeolithic and modern reindeer antler were analysed using complementary techniques to evaluate the conservation state of bone material. X‐ray diffraction, FT‐IR spectroscopy, scanning electron microscopy (SEM–EDX) and transmission electron microscopy (TEM–EDX) as well as proton induced X‐ray and γ‐ray emission (PIXE–PIGE) at the particle accelerator AGLAE, C2RMF were applied. This study enabled us to define the chemical and structural features of ancient antler at the micro‐ and nanometre scale and compare them to those of other bone materials such as bone and ivory. Antler is richer in its organic fraction compared to bone and ivory. Its mineral fraction, carbonated hydroxylapatite, shows very specific crystal shapes at the nanometre scale. This specific property allowed us to recognize antler traces in pigment samples originating from rock art paintings in the Lascaux cave, Dordogne, southwestern France, Magdalenian period. Therefore, TEM–EDX is the technique of choice for characterizing antler traces in complex mixtures. In the paint material of Lascaux, antler seems most likely to be a pollutant introduced either by stirring the pigments in water with a piece of antler or by carving antler artefacts next to the preparation of paint material. However, it could eventually be used as a marker of paintings that were created contemporaneously.     

Savoury Recipes and the Colour of the Tlatelcomila Human Bones

Bones from Tlatelcomila (Tetelpan, México D.F.) were characterized by several complementary physical and chemical techniques, such as X‐ray diffraction, scanning electron microscopy, transmission electron microscopy, atomic force microscopy, energy‐dispersive spectroscopy and ultraviolet spectroscopy, to determine whether they were boiled or grilled. The usual correlation between thermal treatment and colour is revisited in terms of microscopic structure, morphology and texture. At temperatures less than 100°C, it is shown that colour depends not only on temperature or diagenesis but also on the cooking procedure; that is, on the presence of spice dyestuffs such as axiote (Bixa orellana) or chilli (Capsicum).     

FIELD AND LABORATORY MULTI‐TECHNIQUE ANALYSIS OF PIGMENTS AND ORGANIC PAINTING MEDIA FROM AN EGYPTIAN COFFIN (26TH DYNASTY)

This paper describes the physico‐chemical analyses performed on an Egyptian wood coffin on the occasion of its restoration in the hall of the National Archaeological Museum of Parma (Italy), with the aim of investigating the pigments and organic materials originally used. Pigment determination was performed both in situ by a portable energy‐dispersive X‐ray fluorescence (EDXRF) spectrometer and in the laboratory using a micro‐Fourier‐transform‐infrared (micro‐FTIR) and a Fourier‐transform (FT) Raman spectrometer. The identification of organic materials was performed through gas chromatography – mass spectrometry (GC–MS) and micro‐FTIR analysis. Amongst the pigments, special attention was paid to the green, which appeared to be severely degraded and was examined using powder X‐ray diffraction (XRD) and scanning electron microscopy – energy‐dispersive X‐ray (SEM–EDX) in addition to the above‐cited techniques. Other materials used in the polychromatic decorations are Egyptian blue, cinnabar and possibly orpiment, while calcium carbonate was used for the ground layer. The organic materials were identified as beeswax, mastic and gum arabic, sometimes as mixtures.     

Identification of Pigments in Hellenistic and Roman Funeral Figurines

Microsamples removed from funeral figurines, which were found in two Hellenistic (third to second centuries bc ) and two Roman (first to second centuries ac ) tombs in the centre of Thessaloniki, Greece, are investigated following a multi‐analytical approach. Polarized light microscopy (PLM), X‐ray fluorescence (XRF) spectroscopy, micro‐Raman spectroscopy and high‐performance liquid chromatography coupled with a diode array detector (HPLC–DAD) are employed to identify both inorganic and organic pigments. PLM is useful to reveal the combinations of the colourants, which are identified as follows. Red ochre, cinnabar, yellow ochre, Egyptian blue, carbon black, calcite, dolomite and quartz are identified using XRF and Raman spectroscopy. HPLC–DAD is used to identify the organic colourants, which are rarely detected in painted objects of the Hellenistic and Roman period. In particular, cochineal and madder are found in six samples extracted from Hellenistic figurines. This is the first study describing the unequivocal identification of cochineal in Hellenistic objects. Furthermore, madder is identified in one sample dated to the Roman period. Madder lakes detected in the samples contain high amounts of purpurin; alizarin is either not detected or detected in trace amounts.     

A SCIENTIFIC INVESTIGATION ON THE PROVENANCE AND TECHNOLOGY OF A BLACK‐FIGURE AMPHORA ATTRIBUTED TO THE PRIAM GROUP*

The restoration of a Greek black‐figure amphora provided an opportunity to study the provenance and production technology of the vase. The composition of the ceramic body, determined by inductively coupled plasma optical emission spectroscopy (ICP–OES), matches that of Attic products. Investigation by X‐ray diffraction and reflectance spectroscopy suggests a maximum firing temperature around 900°C and a body re‐oxidation temperature around 800°C, respectively. The morphology and composition of black, red and dark red surface areas were studied by scanning electron microscopy and X‐ray energy‐dispersive analysis; the black areas show the features of a typical well‐vitrified black gloss, while the red areas were most probably obtained by simple burnishing of the body; the dark red additions, on the other hand, are the likely result of a partial re‐oxidation of a clay–ochre mixture.     

The Belgammel Ram,a Hellenistic‐Roman Bronze Proembolion Found off the Coast of Libya: test analysis of function,date and metallurgy,with a digital reference archive

The Belgammel Ram was found off the coast of Libya in 1964, and examined during 2008–9. The following techniques were used: surface non‐contact digitizing using a laser scanner, reflectance transformation imaging using polynomial texture mapping and hemi‐spherical harmonics, digital photogrammetry with dense surface modelling, structured light optical scanning, and X‐ray fluorescence analysis. For internal structure the ram was examined by X‐radiography and 3‐D X‐ray tomography. Metallurgical composition was studied by micro‐drilling and subjecting the samples to scanning electron microscope X‐ray micro‐analysis, micro X‐ray fluorescence and X‐ray backscatter. The lead isotope composition was analysed. The alloy has average percentage composition Cu = 86.9, Sn = 6.3, Pb = 6.6, and Zn = < 0.10. The Belgammel Ram is probably a Hellenistic‐Roman proembolion from a small military vessel or tesseraria. The archived data are at the Faculty of Engineering and Environment, Engineering Sciences, Material Data Centre, University of Southampton ( muvis@soton.ac.uk ).     

Compositional Analysis by p‐XRF and SEM–EDX of Medieval Window Glass from Elgin Cathedral,Northern Scotland

Thirty shards of medieval window glass from Elgin Cathedral in north‐east Scotland have been subjected to compositional analysis by portable X‐ray fluorescence and scanning electron microscopy – energy‐dispersive X‐ray spectroscopy. Comparison with previous analytical studies suggests that the majority of the glass was probably produced in France, while a smaller group may have been made in Germany. Significant differences in base glass composition were observed between colours. Two distinct blue glasses compositions were identified. The composition of the grisaille paint differs from paint on the continent, providing the first evidence that it was made using local Scottish lead and iron pigments. This work represents the largest analytical study of Scottish medieval window glass yet undertaken and presents insights into the transfer of medieval materials, technologies and trade routes.