Identification of Green Pigment Used in Persian Wall Paintings (ad 1501–1736) Using PLM,FT–IR,SEM/EDX and GC–MS Techniques

The technique of oil painting was introduced to Iran via a cultural exchange with Europe in the Safavid period (ad 1501–1736). Since the first attempt at scientific conservation of wall paintings in Iran in the 1960s, the nature of green pigment used in Persian wall paintings has not been clear, although work on contemporary miniature paintings has identified malachite and verdigris. PLM, FT–IR, SEM/EDX, GC–MS and the study of contemporary historical treatises of the Safavid period were the main tools used in the present study to identify the green pigments in Persian (oil‐based) wall paintings. Eight samples taken from the two famous Safavid buildings, Chehel Sotoon Palace and the Sukias House in Isfahan, were analysed. Here, the identification of copper‐based pigment and of verdigris in oil as oleate amends the existing knowledge of the green pigment used in these paintings. It also suggests that oleate was introduced to Persian artists via the European influence on Persian painting as a result of cultural exchange in the Safavid period, when the technique of Persian painting changed from tempera to oil painting. However, as verdigris in oil and resin can appear as oleate over time, it is unknown whether the Persian artists did this deliberately or accidentally.     

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.     

DISCOVERY AND CHARACTERIZATION OF AN UNKNOWN BLUE‐GREEN MAYA PIGMENT: VESZELYITE*

Blue‐green mosaic and polychrome masks and funerary offerings from the royal tombs of Calakmul, Mexico, were analysed by scanning electron microscope equipped with energy dispersive X‐ray spectroscopy (SEM‐EDS), X‐ray diffraction (XRD), and particle induced X‐ray emission (PIXE). This led to the first identification of the use of veszelyite, a rare hydrated copper‐zinc phosphate, as green pigment. Analyses of a geological sample of this mineral have been done to confirm the characterization of this Mayan pigment, which might help determine pre‐Columbian trade routes of precious and luxury objects in the ancient Maya Classic period (ad 250–800).     

THE EGYPTIAN GREEN PIGMENT: ITS MANUFACTURING PROCESS AND LINKS TO EGYPTIAN BLUE*

The chemical and structural analysis of raw Egyptian blue and green pigment cakes and of 50 pigment samples taken from paintings kept in the Louvre Museum was performed using a set of analytical techniques (X‐ray powder diffraction, transmission and scanning electron microscopy, Raman microscopy and UV spectrophotometry). The structural and morphological study of modern samples prepared on the basis of these results has provided technological data that help to explain ancient procedures. The role of the firing temperature, the atmospheric conditions in the furnace and the cooling rate are considered. The difference between Egyptian blue and Egyptian green pigment is proved. Manufacturing processes for their deliberate synthesis are proposed.     

IDENTIFYING THE PLANT ORIGIN OF ARTISTS' YELLOW LAKE PIGMENTS BY ELECTROSPRAY MASS SPECTROMETRY

Dyes containing flavonoids are found in yellow lake pigments used as artists' materials. Pre‐treating a sample of a flavonoid‐based lake pigment with an acidic ion exchange resin followed by reversed‐phase HPLC electrospray mass spectrometry enables the identification of key diagnostic yellow compounds, even when the pigment is bound in paint media. Reference raw plant materials of weld and buckthorn berries were also treated similarly for comparison with the lake pigments derived from these plants. This method is suitable for microsamples and thus suitable for analysis of samples that can be ethically removed from works of art in the course of their conservation. The flavonoid content is analysed and plant origins are suggested for yellow lake samples taken from Reclining Tiger by Jean‐Baptiste Oudry and the 1893 version of The Scream by Edvard Munch.     

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.     

山东临淄山王村俑坑出土陶质彩绘颜料初步分析

2008年5月山东临淄山王村俑坑出土了数量较多的彩绘陶质文物,为了了解彩绘颜料结构和成分,采用粉末偏光显微法、剖面观察结合拉曼光谱分析对彩绘文物表面颜料样品进行分析。结果表明,这批陶质文物表面彩绘是以白灰做地仗层,由碳酸钙、白土、铁黑（Fe₃O₄）、铁红（Fe₂O₃）、朱砂等颜料调和而成,且厚度不均。在个别样品中发现了少量的中国蓝颗粒(BaCuSi₄O₁₀),这是这次分析中较为重要的发现,此分析结果也可为考古研究提供科学信息。     

Examination of some pigments,grounds and media from Egyptian cartonnage fragments in the Petrie Museum,University College London

A number of cartonnage fragments from the collections of the Petrie Museum, UCL, were examined to identify pigments, media and grounds. The different types of cartonnage made in ancient Egypt are reviewed. Special attention was paid to green pigments, which were shown to be of green earth, or a mixture of Egyptian blue and a yellow, usually goethite or orpiment. Green earth was found in one artefact, dated to the 9th century BC: all other examples were from the Graeco-Roman period. No copper-organometallic greens were present in the examples studied, or Egyptian green, or malachite. Binding media was identified both by ELISA and by GC/MS. A pink colourant was identified as madder, while lead white was used as a white in one example, showing the influence of Roman and Greek pigments on Egyptian art in these later periods. Plant gum, egg, and animal glue were found in different fragments, with mixed media in a few cases. Moganite was found associated with quartz in some preparatory layers by X-ray diffraction, which has not been reported previously as a constituent of ground layers in Egyptian artefacts.     

Coloured Prints of the 16th Century: Non‐Destructive Analyses on Coloured Engravings from Albrecht DÜrer and Contemporary Artists

Qualitative investigations of pigments and dyes using micro X‐ray fluorescence spectrometry (micro‐XRF) and visible spectrophotometry (VIS) are suitable non‐destructive methods for the characterization of different colorants in art objects. In this study, several rare coloured engravings from the work of Albrecht Dürer—and, in addition, from the work of Cornelis Cort, Servatius Raeven and Johannes Sadeler—were investigated. The analyses result in specific palettes of colours that were used by different artists or in different workshops for the coloration of engraved images. Starting from these different palettes, it is possible to distinguish coeval colorations that were added in the 16th century from those that were carried out at a later date (e.g., the 19th century).     

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.     

Bitumen in Early Ceramic Art: Bitumen‐Painted Ceramics From Late Neolithic Tell Sabi Abyad (Syria)*

The paper presents the results of a chemical analysis of black pigment used to decorate pottery from Late Neolithic Tell Sabi Abyad, northern Syria (c. 6100 cal bc ). The pigment appears to be bitumen. A comparison with known reference samples from modern locations of bituminous sources in the Near East suggests that the bitumen used to paint ceramics at Tell Sabi Abyad came from at least two different source areas in northern Iraq. The bitumen‐painted ceramics at Tell Sabi Abyad represent the earliest evidence attested so far of bitumen used as a pigment for pottery decoration.     

甘肃泾川出土5件佛教造像彩绘分析及相关研究

运用显微观察、荧光拍照、偏光显微镜、X射线荧光光谱、X射线衍射及扫描电镜能谱分析手段,对#87北魏造像碑、#99隋代佛头、#54宋代残破佛头和2件泥塑佛像残块表面彩绘进行研究。结果显示,北魏和隋代造像红色为朱砂,绿色为石绿,白色为方解石;隋代造像面部肉色为硫酸铅和朱砂的混合物,眼黑为炭黑;宋代造像表面红色为铁红,白色为方解石;泥塑残块#1表面蓝色为石青和石绿的混合物,#2表面为朱砂,判断其制作年代不晚于唐代中期。白灰层主要成分为碳酸钙,并具有亮白色荧光反应,与碳酸钙粉末混合有机胶制成白灰层的荧光反应一致,判断古代样品白灰层中可能存在有机胶结质。在元素分析过程中,铅(Pb)一直存在,而在物相分析中并没有发现Pb的化合物。同样问题在早期关中出土墓葬壁画分析中同样存在,是否与彩绘工艺本身有关,值得引起关注。     

A Study of Biodeterioration and Chromatic Alterations of Painted and Gilded Mummy Cartonnage at the Saqqara Museum Storeroom,Egypt

Microbial biofilms have developed on the surfaces and within the painted and gilded layers of mummy cartonnage at the Saqqara museum storeroom in Giza, Egypt. SEM–EDX, XRD and FT–IR–ATR techniques were applied to analyse the coloured and gilded materials, ground layer, textile support and binder used for the cartonnage. Aspergillus niger (24.8%), Penicillium chrysogenum (21.5%) and a novel cartonnage‐biodegrading bacterium, Bacillus sonorensis (23.7%), were the most abundant microbes growing over the cartonnage surface. In addition, Aspergillus tamari (15.4%), A. fumigates (8.1%) and Fusarium solani (6.5%) were identified. The pigments comprised Egyptian blue (cuprorivaite), cinnabar (red), orpiment (yellow) and green pigment made from a mixture of cuprorivaite and orpiment. Gold leaf was used for the gilded layer, calcium carbonate and gypsum comprised the ground layer, gum arabic was the binding medium and the fibre base was a fine linen textile. Microbial colonization tests were performed on aged cartonnage replica samples made from linen and pigments of similar composition to ancient pigments found in the cartonnage. Each sample was inoculated separately with A. niger, P. chrysogenum and B. sonorensis. Yellow orpiment samples were the exception, as no colour change was detected after colonization by the examined micro‐organisms.     

Evaluating Ancient Whale Exploitation on the Northern Oregon Coast Through Ancient DNA and Zooarchaeological Analysis

Whales have long been an important part of Pacific Northwest Coast human subsistence and lifeways. Native peoples on the Oregon Coast were not known to hunt whales, but a humpback whale phalange with an embedded bone harpoon at the Par-Tee site (35CLT20) and ethnographic accounts raised the possibility of opportunistic whale hunting. We analyzed a suite of whale remains from Par-Tee and performed ancient DNA-based species identifications on 30 specimens. The assemblage includes gray whales (Eschrichtius robustus, 60.7% of the assemblage), humpbacks (Megaptera novaeangliae, 32.1%), minkes (Balaenoptera acutorostrata, 3.6%), and orcas (Orcinus orca, 3.6%). While the species composition is similar to those found in archaeological deposits from systematic whaling areas in Washington and Vancouver Island, bone modification patterns and element representation reveal important differences. Our analysis demonstrates that whales were likely a supplementary part of human subsistence at Par-Tee and, while opportunistic whale hunting likely occurred, it may have been secondary to scavenging and utilization of beached and/or drift whales.     

„On employera les meilleurs Graveurs pour les Figures”︁. Zeichner und Stecher der Berliner Akademie der Wissenschaften, 1700–1806

“We will employ the best engravers for the figures” – Draughtsmen and Engravers of the Berlin Academy of Sciences, 1700–1809. – Although barely mentioned in accounts of its history of the Berlin Academy of Sciences, draughtsmen and engravers were, from the very inception, essential collaborators. Based on previously overlooked archival sources, this paper investigates the strategies that scientists used to select the most appropriate candidates during the first hundred years of the academy's existence. These included: (1) the engaging of artists already known to the scientists or those who had been recommendaded to them; (2) maintaining long‐term relationships with a number of artists, and later with their offspring (who had frequently been trained by their fathers); in 1768 this strategy culminated in the creation of a permanent position for one academic draughtsman; and (3) hiring draughtsmen who specialised in the subject matter in question, which entailed, for example, employing different people to carry out anatomical and botanical illustrations.     

Reflections on North American Pacific Coast prehistory

The Pacific Coast of North America was occupied by many distinctive groups of coastal hunter-gatherers at the times of early contacts with Europeans. Despite significant cultural diversity, Pacific Coast peoples shared lifeways oriented toward generally similar marine, nearshore, littoral, and estuarine habitats. In this paper, we examine some major issues that guide much of the archaeology done along the Pacific Coast, then discuss some of the theoretical and methodological problems that limit the efficacy of archaeological reconstructions. Most archaeological research conducted on North America's Pacific Coast has been oriented toward the search for the origins and development of a variety of cultural patterns. A comparative review of California and Northwest Coast sequences provides interesting parallels and discrepancies in the approaches taken in studying some of the major issues in Pacific Coast prehistory.     

A STUDY ON LATE MEDIEVAL TRANSPARENT‐GLAZED POTTERY AND ARCHAIC MAJOLICA FROM ORVIETO (CENTRAL ITALY)*

Nineteen samples of medieval transparent‐glazed pottery and archaic majolica from Orvieto (central Italy) were studied. They were classified by archaeological criterion as follows: five transparent‐glazed fragments with green and brown decorations (first half of the 13th century), eight green transparent‐glazed fragments (13th century) and six tin‐glazed fragments with green and brown decorations (second half of the 13th century). SEM–EDX, XRD (the Rietveld method) and XRF were used to characterize the chemical and mineralogical compositions both of the bodies and the coatings. In all of the samples, the paste is Ca‐rich with CaO contents as high as 13–20 wt%. The mineralogical composition is compatible with a firing temperature of about 950°C, which is the typical temperature reached in a wood kiln. No difference was observed between the bodies of transparent‐ and tin‐glazed pottery. In the case of transparent glazes, the burial conditions lead to heavy weathering of the samples. However, on the basis of the analyses carried out in non‐weathered areas, the typical composition is PbO 55–65 wt%, SiO₂31–35 wt%. In tin glazes, the tin is scattered on the mass of the glaze as SnO₂crystals with a concentration of 7–14 wt%. Concerning the decorations, it is established that the green colour is due to the presence of copper, while manganese is responsible for the brown colour. These pigments, which represent the typical colours of ‘archaic majolica’, are spread through the glaze homogeneously, apart from one case in which there is clear evidence of manganese oxide crystals.     

ICP–MS ANALYSIS OF GLASS FRAGMENTS OF PARTHIAN AND SASANIAN EPOCH FROM SELEUCIA AND VEH ARDAŠ?R (CENTRAL IRAQ)*

Forty‐one glass fragments were analysed by inductively coupled plasma – mass spectrometry, determining 40 major, minor and trace elements, including rare earth elements. The fragments came from excavations carried out at the archaeological sites of Seleucia and Veh Arda??r in modern Iraq, and were dated to the Parthian and Sasanian epochs. Analytical data indicate that all the samples are silica–soda–lime glasses. Magnesium and potassium oxide contents below 1% suggest that eight out of nine glasses from Seleucia, dating from between the first and the third century ad , could have been obtained by use of an evaporite as a flux; the same conclusion can be drawn for some of the Sasanian glasses dating from the fourth and fifth centuries ad . The other glasses from Veh Arda??r, as well as the remaining sample from Seleucia, are characterized by higher contents of magnesium and potassium, which suggests recourse to plant ash; different magnesium and phosphorus contents allow one to separate these samples into two main groups, pointing to the use of different kinds of plant ash. Aluminium and calcium contents, together with trace element data, may indicate that different sands were used for preparing glasses of different composition. Samples from Seleucia and Veh Arda??r are mainly blue–green and green to yellow–green, respectively; iron and manganese contents suggest that the furnace atmosphere was mainly responsible for the development of these hues.     

PIGMENT IDENTIFICATION IN GREEK POTTERY BY RAMAN MICROSPECTROSCOPY*

Raman microspectroscopy (RMS) is now established as a key technique for the identification of pigments of archaeological pottery that permits the in situ study of art objects by a non‐destructive procedure. The information obtained represents a great aid to restoration and conservation techniques. In this work, the chemical nature of the red, black and white pigments of five samples of Greek pottery from the end of the fifth century and the first half of the fourth century bc , exhumed from the Iberian necropolis of Cabezo Lucero (Guardamar del Segura, Alicante, Spain), has been identified. The black and the red pigments are found to be magnetite (Fe₃O₄) and hematite (α‐Fe₂O₃), respectively. The white pigment is found, for the first time, to be composed of alumina (α‐Al₂O₃ and γ‐Al₂O₃) probably yielded by the thermal decomposition of Greek bauxite.