Chemical and mineralogical characterization of Aguada Portezuelo pottery from Catamarca,north-western Argentina: PIXE,XRD and SEM-EDS studies applied to surface pre- and post-firing paints,slips and pastes

Particle-induced X-ray emission (PIXE), X-ray diffraction (XRD), electron microprobe analysis (EDS) and scanning electron microscopy (SEM) analytical techniques were used to characterize surface paints in pre- and post-fired Aguada Portezuelo decorated pottery. Surface paintings in black, white, red, brown, burgundy and ochre were analysed. Major, minor and trace elements were detected by PIXE, whereas XRD and SEM-EDS gave information on the main mineral phases and the characteristic morphology for each analysed pigment. The results obtained indicate that the main colour groups can be easily discriminated by PIXE, and they are characterized by only one pigment for each colour: hematite (red) and manganese mineral oxides (black), respectively, whereas white pigments are characterized by calcite, ghelenite and gypsum.     

The painting of the Etruscan “Tomba della Quadriga Infernale” (4th century BC), in Sarteano (Siena, Italy): technical features

This work presents the results of an investigation of the painting technique used in the Etruscan tomb “Tomba della Quadriga Infernale”. This tomb was discovered in Sarteano (Siena, Italy) in October 2003 and dated back to the second half of the 4th century BC. Red, dark red, pink, yellow, white, black, and grey colours were used in the tomb in order to create paintings, which now represent a very precious record of the Etruscan art of wall painting in a hypogeal environment. The technical features of the painting were revealed by stratigraphy using optical and electronic microscopy. The components and preparatory layers of the painted areas were characterized using Fourier transform infrared spectroscopy (FTIR), energy dispersive X-ray microanalysis (SEM-EDS), X-ray diffraction (XRD), and gas chromatography/mass spectrometry (GC/MS). XRD, SEM-EDS, and optical microscopic techniques were also used for mineralogical analysis of the rock substrate. The SEM-EDS and FTIR analyses showed that red and yellow ochre, calcite, and vegetable charcoal were used to paint the walls of the tomb: the pigments, either alone or mixed together, were utilized to produce pure colours (red, yellow, white, and black) and intermediate tonalities (pink, dark red, and grey). SEM-EDS, FTIR, and XRD highlighted that the painting was made on a preparatory layer of calcite, applied onto a levelling material made up of calcite, clay minerals, quartz, and iron oxides. GC/MS analyses revealed that egg was used as an organic binder to disperse the pigments.     

A preliminary study on the role and implication of plate-type iron artifacts in the ancient iron technology of Korea

Special iron objects in the form of a narrow plate with a fan-shaped blade on one or both ends, but with a substantial variation in shape and size, have continually been excavated from ancient historical sites located in the southern part of the Korean peninsula. The frequency and abundance of their excavation imply that they must have played a crucial role in the initial shaping of the Korean iron industry. Little is known, however, of their intended purposes or the exact engineering processes applied in their production. Speculation suggests that they might have been used as currencies or intermediate materials for the making of finished products. This study examined the microstructures of three such iron objects from the Korean Three Kingdoms Period (ca. 300–600 AD). It was determined that they were made of low carbon iron generally containing a number of non-metallic inclusions, with hints of surface carburization particularly at the ends of the plates. These results reveal the likely presence of an iron technology based primarily on the bloomery technique as opposed to the Chinese style of iron-making based on cast iron technology, which was also in use in ancient Korea.     

GC–MS ANALYSIS OF LIPIDS IN PREHISTORIC ROCK PAINTS AND ASSOCIATED OXALATE COATINGS FROM THE LOWER PECOS REGION,TEXAS*

The presumption that lipids were used as binders/vehicles in pictograph paints from southwestern Texas was tested using gas chromatography–mass spectrometry (GC–MS). A one‐step transesterification/derivatization procedure was used to convert bound and unbound fatty acids to fatty acid methyl esters for the analysis. Approximately 30 organic compounds were detected in the natural rock coating that encapsulates the paints, but there were no compounds unique to the paints. Moreover, the C_16:0 and C_18:0 concentrations in the paint samples were similar to the concentrations of these fatty acids in the rock coating, indicating that the compounds are native to the patina. Thus, lipid binders were either not used in the original paint mixture or have since degraded.     

A multi-technique characterization and provenance study of the pigments used in San rock art, South Africa

During the course of a conservation project at the rock shelter known as RSA TYN2 (Eastern Cape, South Africa), a sample of 33 painted fragments that had become detached from the wall were collected. They have been studied using a multi-technique approach (optical microscopy, SEM-EDS, Raman spectroscopy and FTIR), with the aim of achieving a better understanding of their paint stratigraphy, composition, and provenance. The paintings are on a Clarens Formation sandstone and are embedded in calcium sulphates and oxalates. The red pigments show two different ‘hues’, corresponding to two different compositions. The light red is a red ochre, possibly pure, which is probably a degradation product of the Clarens Formation sandstone. The dark red contains more iron oxides and may be a mixture between the red ochre and pure haematite. Because of the presence of crystals which may be identified as augite we suggest this haematite came from the basaltic upper part of the Drakensberg, at least 4 km away from the rock shelter. The black pigments have been identified as carbon black, that is to say, incomplete combustion products of organic compounds, and are radiocarbon dated to between 2120 and 1890 cal BP, making these samples the oldest directly dated South African rock art.     

陕西蓝田水陆庵彩绘泥塑颜料分析研究

水陆庵位于陕西蓝田王顺山下,庵内现存三百余平方米精美绝伦的明代彩绘泥塑,是我国泥塑保存最多、最完整的明代彩绘泥塑群之一。为明确水陆庵彩绘泥塑的颜料使用情况,采用光学显微镜、X射线衍射仪、显微红外光谱仪、扫描电镜-能谱仪和显微拉曼光谱仪对颜料样品进行科学分析。结果表明,除中隔壁背面重妆区域的蓝色颜料主要成分是普鲁士蓝之外,水陆庵彩塑使用的颜料大多为矿物颜料,包括铅丹、朱砂、铁红、氯铜矿、雌黄和云母等。研究结果将为水陆庵后续保护修复提供科学依据,并为丰富关中地区明代彩绘泥塑颜料类型补充科学信息。     

Automated Analysis of Environmental Degradation of Paint Residues

The development of effective conservation strategies for the protection of rock art sites involves the assessment of the taphonomic risks posed by physical and chemical weathering. This study outlines the methodology used in a pilot study to monitor and model the deterioration of paint residues in a cave environment. Mineral oxide pigments were mixed with water and placed on the walls of a cave in the Mendip hills (U.K.). The physical degradation of the paint residues was simulated visually and modelled mathematically. A training stage learning the characteristics of a reference image is followed by comparisons with this image as the test paints deteriorate. The study will be extended over three years and digital image processing will be used to quantify changes in the colour and dimensions of the test paints. The results will be correlated with micro-climatic variables. This methodology can be used to model taphonomic changes to rock art and other forms of imagery in differing environments.     

In‐situ Sourcing of Hematite Paints on the Surface of Hohokam Red‐on‐Buff Ceramics Using Laser Ablation – Inductively Coupled Plasma – Mass Spectrometry (LA–ICP–MS) and Instrumental Neutron Activation Analysis

Worldwide applications of ochre analysis continue to develop at a rapid pace, highlighting a number of analytical and interpretative issues. As regional source databases continue to grow, researchers have turned to the thornier issues of source allocation. In this study, we utilize LA–ICP–MS and NAA to examine archaeological pigments, ceramic paints and experimental tiles from geological sources and Hohokam ceramics in central Arizona. Archaeological pigments and paint on sherds are successfully source matched based on trace element content, with implications for understanding paint production, sociocultural relations governing trade in pigment and the use of different resource landscapes over time.     

秦始皇帝陵园出土彩绘青铜水禽表面彩绘工艺研究

为全面了解秦始皇帝陵园出土青铜水禽表面彩绘装饰工艺的技术内涵,利用显微观察、偏光显微鉴定、拉曼光谱分析等手段,对秦始皇帝陵园K0007陪葬坑出土彩绘青铜水禽表面彩绘装饰工艺进行了系统的考察和研究。研究结果显示,白色颜料为骨白,黑色颜料为炭黑;彩绘层为多层绘制而成,在结构上与秦陵出土陶俑、陶马表面彩绘具有明显区别;彩绘绘制技法包括平涂及堆绘两种,其中堆绘主要用于羽毛纹路羽轴的绘制,施彩工具可能为毛笔或毛刷。彩绘作为青铜器的装饰工艺主要出现于秦汉时期,但并没有得到广泛应用,可能与彩绘装饰自身的脆弱性以及青铜器的功能由礼容器转变为实用器有关。     

Investigations of Byzantine glass bracelets from Nufăru,Romania using external PIXE–PIGE methods

The chemical composition of twenty glass bracelet fragments found in Nuf?ru, a Byzantine site from 10th–13th centuries A.D., nowadays located on Romania's territory, has been determined using Particle Induced X-ray Emission (PIXE) and Particle Induced Gamma-ray Emission (PIGE) in external beam mode. Most of the Byzantine bracelet fragments were identified as “mixed natron-plant ash” soda-lime-silica glasses. The obtained chemical compositions indicated that the manufacturing of these finery items was performed using similar raw materials and techniques, in most of the cases involving colored glass recycling. PIXE–PIGE results highlighted the glass chromophores (cobalt, manganese, copper and iron ions) and provided hints about the mineral pigments used to paint the external surface of some bracelets.     

湖南桃源出土战国彩绘陶器的科学分析

为研究湖南桃源县战国楚墓出土彩绘陶器的组成结构及保存现状,采用能量色散X射线荧光光谱法(EDXRF)、扫描电镜-能谱法(SEM-EDS)、X射线衍射法(XRD)和激光拉曼光谱法(LRS)等手段对陶器胎体成分、表面彩绘、金属涂层等进行分析检测。结果表明:这批彩绘陶器胎体成分相近,为普通易熔黏土。彩绘陶器表面的红色颜料为朱砂(HgS),黑色颜料为炭黑(C)。在彩绘陶壶、陶鼎和陶敦表面发现金属涂层装饰,通过扫描电镜能谱和X射线衍射分析,确定涂层为单质锡,属于锡涂陶的范畴。同时红外光谱测试显示锡层内面棕黑色物质为生漆,可能混合其他胶结材料。以上结果为研究战国时期彩绘陶器,特别是锡涂陶的制作工艺及发展提供了新的资料。     

The restored opus sectile panel from the luxurious episcopal residence in the ancient city of Stobi–mineralogical and chemical findings

Samples from the opus sectile panel excavated from the Episcopal Residence building at the archaeological site of Stobi were examined using X-ray powder diffraction, SEM-EDS, and Raman spectroscopy. The analyzed samples, exhibiting plentiful color and surface variations, comprise the reconstructed sectile panel as well as represent the in situ ground remains. The complementary techniques revealed dominant amorphous phase in five samples, whereas the remaining seven specimens confirmed the presence of magnesite, quartz, dolomite, ankerite, cuprite, wüstite, and hematite. The work represents the first systematic attempt to determine the mineral phases in the restored opus sectile panel, assembled by decorative minerals forming a geometric net of polychrome crosses. Furthermore, the mineral characterization has revealed an origin of mineral species not typical for Macedonian terrain (ankerite, wüstite, cuprite, transparent quartz) that lead to the conclusion that the samples were likely imported from other early-Christian communities.     

陕西杨家湾出土西汉彩绘兵马俑的修复保护研究

陕西咸阳杨家湾出土的西汉彩绘兵马俑出现大面积严重风化褪色现象及彩绘层严重脱落、起翘,应尽快采取抢救性保护措施对其进行保护。在系统分析了该批彩绘兵马俑的病害种类及其产生原因后,通过XRD、SEM—EDS和Micro FT-IR对其彩绘颜料成分进行了分析。此基础上,制定了一个系统的修复方案,选取了合适的修复工艺及修复保护剂。结果表明,三乙氧基硅烷缩合而成的树脂胶材料对彩绘层进行回帖后,其强度有了明显的增强。经过自行研制的RFC显现加固剂处理后的彩绘颜色显现出了其古朴清晰的原貌,且颜料附着力增强。     

A SPECTROSCOPIC INVESTIGATION OF PIGMENT AND CERAMIC SAMPLES FROM COPÁN,HONDURAS*

A combination of micro‐Raman spectroscopy, micro‐infrared spectroscopy and SEM–EDX was employed to characterize decorative pigments on Classic Maya ceramics from Copán, Honduras. Variation in red paint mixtures was correlated with changing ceramic types and improvements in process and firing techniques. We have confirmed the use of specular hematite on Coner ceramics by the difference in intensities of Raman bands. Different compositions of brown paint were correlated with imported and local wares. The carbon‐iron composition of the ceramic type, Surlo Brown, was confirmed. By combining micro‐Raman analysis with micro‐ATR infrared and SEM–EDX, we have achieved a more comprehensive characterization of the paint mixtures. These spectroscopic techniques can be used non‐destructively on raw samples as a rapid confirmation of ceramic type.     

Mineralogical analysis and provenancing of ancient ceramics using automated SEM-EDS analysis (QEMSCAN®): a pilot study on LB I pottery from Akrotiri,Thera

A wide range of existing mineralogical and geochemical methodologies such as optical microscopy, X-ray diffraction, manual scanning electron microscopy, ICP-MS and INAA have been utilised in the analysis of ancient ceramics, in attempts to elucidate patterns of regional trade and interaction. However, advances in automated scanning electron microscopy with linked energy dispersive spectrometers (SEM-EDS) have created the potential to offer a seamless combination of textural and mineralogical data based on the acquisition of energy dispersive spectra that has so far been unattainable with existing techniques. In this pilot study on pottery from the Cycladic Bronze Age site of Akrotiri (Thera), we have quantified the mineralogy of the ceramics based on automated SEM-EDS using QEMSCAN^® technology and imaged the textures of the ceramics through compositional mapping. Thirteen samples were analysed and, based upon the automated analysis, four groups of ceramic compositions are defined. These data are consistent with, but also refine, previous traditional petrographic examination of the ceramic samples, and enable the likely provenance of the raw materials used in the ceramic manufacture to be identified. This technique allows the acquisition of fully quantitative data, not only for the larger inclusions within the ceramics but also for the typically finer-grained groundmass/matrix, whilst also providing the overall texture of the ceramic.     

An assessment of the magnetic response of an iron‐smelting site*

The magnetic response derived from an iron‐smelting site was investigated by comparing magnetometry and magnetic susceptibility geophysical survey data and laboratory analyses of the magnetic characteristics of the furnace and slags. Magnetic analysis and microscopy (optical and SEM) of samples from the furnace lining and the slag deposits demonstrated the heterogeneity in the magnetic, morphological and mineral compositions of both materials. The comparison of the magnetic characteristics of the material with the geophysical survey data illustrated the importance of using both magnetometry and magnetic susceptibility survey techniques to maximize the information from an iron‐smelting site. The furnace was dated archaeomagnetically to the 14th century ad . The results demonstrate that the magnetic analysis of iron‐smelting sites is highly valuable, both to characterize sites and to improve the understanding of early iron‐working technology.     

永乐宫壁画制作材料及工艺的初步调查分析

永乐宫原位于山西省芮城县永乐镇,建于1247—1368年,是为纪念吕洞宾而修建的。其壁画绘制700多年来,历经多次自然灾害和修缮,还经历了20世纪60年代的整体搬迁,目前壁画已出现常见的颜料层起甲、脱落、粉化等病害,还存在拼接缝开裂起翘,表层画面受污染变色的状况。由于早期切割、搬迁和修复的大量介入,现存壁画表面及内部结构都发生了巨大的变化。永乐宫在搬迁过程中保存下来的少量壁画残块,一定程度上代表了永乐宫壁画的原始状态,是研究早期壁画材料和工艺信息的重要的和极有价值的样本。对此,针对取自永乐宫的11块壁画残块的微量样品,通过光学显微镜(OM)、剖面分析(cross-section analysis)、X射线衍射(XRD)和扫描电镜-能谱(SEM-EDS)等多种分析手段,对其制作材料和工艺进行初步调查分析,并取得了其相关壁画地仗、颜料材质及绘制壁画层位的信息,为永乐宫壁画的科学保护和深入研究提供了重要的基础资料。     

Application of Quantitative Mineralogical Analysis in Archaeological Micromorphology: a Case Study from Barrow Is., Western Australia

This study assesses the use of the Tescan Integrated Mineral Analyser (TIMA) platform, which integrates scanning electron microscopy—energy dispersive spectroscopy (SEM-EDS) chemical analysis with mineral identification software, to quantitatively determine the mineralogical composition of sediments in archaeological research. Ten samples, spanning 50,000 years of sedimentation, were examined from archaeological excavation profiles in the Boodie Cave, Barrow Island, Western Australia. TIMA mineral abundance data show a gradual change from a polymineralogic quartz-rich assemblage from ~50–12 ka to a more simple carbonate-dominate assemblage from the terminal Pleistocene. This trend is consistent with a decreasing contribution of reworked terrestrial siliciclastic sediments derived from the mainland and an increase in carbonate sediments of marine derivation, as the exposed coastal plain become submerged during post-glacial sea-level rise. SEM-EDS analysis has also provided empirical data on cultural materials, mainly bone and shell fragments that similarly reflect the increasing contribution of marine fauna into the Holocene sediments. Particularly useful is the ability of mineral mapping function of the TIMA outputs to help distinguish 16 sub-units representing sections of the main nine stratigraphic units, including at least three contiguous midden events. The SEM-EDS data indicate that the redeposited sediments were derived from the overlying midden unit, with layering reflecting differential settling of mineral phases. This study demonstrates that automated mineralogy studies using TIMA can clearly aid the identification of provenance and processes within archaeological sediments and soils.     

Reliability of a new X-ray analytical microscope in archaeological research

In this report we assess both the reliability and sensitivity of a new X-ray Analytical Microscope (XAM) in specific archaeological studies. The instrument's precision is measured here by its ability to repeatedly produce similar data each time it analyzes the same sample. The accuracy, sensitivity and detection limits of the XAM were evaluated through the quantification of spectra acquired from certified reference materials (CRM), while potsherd identification was assessed by analyzing several potsherds found at different archaeological sites, then correlating their chemical compositions to determine compatibility and possible grouping. Repeatability standard deviation percentages for relative intensity values ranged between 1% and 4% for major elements, while the system's sensitivity for detecting trace elements was in the 50–100 ppm range. Quantification accuracy was excellent with a fitting factor of 0.98 between measured and certified element concentrations. Archaeological potsherds were clearly distinguished according to their elemental compositions, and grouped using bivariate graphs.