ENERGY DISPERSIVE X-RAY FLUORESCENCE ANALYSIS OF ANCIENT COPPER ALLOYS: EMPIRICAL VALUES FOR PRECISION AND ACCURACY

Energy dispersive X-ray fluorescence (EDXRF) analyses are compared with neutron activation as well as atomic absorption analyses of ancient copper-based alloys in order to examine their accuracy and to estimate realistic values for precision and sensitivity of EDXRF. The results show that it is possible to obtain reliable data of the surface composition of objects non-destructively. Better results for bulk composition are usually obtained with drill samples where the sensitivity of the method is at least competitive with atomic absorption spectroscopy with flame atomization.     

Investigation of a Copper-based Hoard from the Megalithic Site of al-Midamman,Yemen: an Interdisciplinary Approach

In 1997, a hoard of copper-based objects was discovered at the megalithic site of al-Midamman, on the Red Sea Tihama coastal plain of the Republic of Yemen. Since there have been very few metal artifacts discovered in the lowlands of Yemen, and there was limited stratigraphy on the site, determining the time and place of production for these artifacts was difficult. A full investigation of the objects was deemed essential to determine their chronology and origin. Analysis included optical microscopy and scanning electron microscopy (SEM) for metallography, inductively coupled plasma spectrography (ICP) for bulk chemical composition, SEM to determine phase composition and corrosion products, and X-ray diffraction (XRD) to identify corrosion products.The objects can be divided into three types of copper and copper alloy: pure copper, arsenic rich copper, and tin rich copper. The difference in composition appears likely to be deliberate and suggests that the objects were produced sometime during the Early Bronze Age through the Middle Bronze Age. Further investigation of any metal objects discovered along the Yemeni coast and along the Ethiopian/ Eritrean side of the Red Sea is obviously essential.     

EDXRF analysis of pigment used for the decoration of Mleiha pottery

Energy dispersive X-ray fluorescence spectroscopy was utilized for the analysis of the elemental composition of pigment used to decorate pottery artifacts belonging to the Mleiha period (3rd c. B.C–3rd c. A.D).     

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。     

Pre-Hispanic gold pieces of an enigmatic archaeological finding in Medellín,Colombia: A glance at an archaeometric analysis

The study analysed pre-Hispanic gold objects found within a surprising archaeological finding of a structure that likely served as a funeral pyre in Medellín, Colombia. ¹⁴C analyses of the site's organic materials dated the structure to the fifth century ce . The metal objects were subjected to X-ray diffraction (XRD), energy-dispersive X-ray fluorescence (EDXRF), scanning electron microscopy-energy dispersive X-ray (SEM-EDX), density measurement by the Archimedes method, and metallographic analysis. The measurements by EDXRF and SEM-EDX showed that the pieces were composed mostly gold and silver. The XRD results indicated that the microstructure of the objects corresponded to a single phase of gold and silver. The images obtained by the metallographic microscope showed equiaxial grains with some twins, a structure consistent with annealed metals. The different colours observed correspond to different grain orientations. Pre-Hispanic objects from a second archaeological site in the municipality of Amalfi (Department of Antioquia) were also analysed for comparative purposes. The results showed that the gold objects were not subjected to any alloying process, but were instead manipulated in their original form (native gold). The shape of the objects and their microstructural results suggested that the pieces were manufactured by casting, mechanical deformation and then annealing.     

A Better Shade of Black: Effects of Manufacturing Parameters on the Development of Ancient Black Bronzes*

Copper alloys with controlled contents of Sn, Ag and Au were treated with methods and solutions that mimic those used in ancient and traditional procedures for the production of black bronze. Examination of the resulting patinas with colorimetry, SEM–EDS, TEM, Raman spectroscopy and XRD revealed no systematic differences according to the fabrication method, whereas patina homogeneity and colour in those alloys that did not contain precious metal were affected by superficial work. Patina microstructure determines adherence and coverage, and depends upon the solution used irrespective of the alloy composition, but the colour of the patina is mainly related to the alloy composition. Gold promotes the development of cuprite, slowing the oxidation to tenorite in the corrosion process. Gold additions produce a more uniform patina as well as a desirable blue–black tone, which is likely to have been a factor in alloy selection.     

X射线显微CT成像技术在金属文物制作工艺研究与腐蚀状态评估中的应用

金属腐蚀过程不仅受环境等外部因素的影响,制作工艺、合金组成及缺陷等内部因素同样起着重要作用。为实现金属文物制作工艺和内部腐蚀状态的可视化研究,运用X射线显微CT对铜镜文物碎片以及出土、海洋出水铁质文物样品进行扫描探测,并结合X射线荧光、X射线衍射等检测手段,开展金属文物材质、工艺及矿化程度的综合分析。结果表明,在显微CT影像重建基础上,通过设定不同的阈值,可实现文物内部缺陷、腐蚀矿化程度等内部信息的测量统计。该方法可为金属文物材质、制作工艺研究和腐蚀状态评估提供无损的研究手段。     

Study on the source of raw material and firing technique of glazed tiles bodies in the Ming Imperial palace site,Nanjing, China

This article considered glazed tiles excavated from the Ming Imperial Palace site in Nanjing as the research object. Glazed tiles were selected and analyzed via vacuum porosimeter, thermal dilation (TD), X-ray diffraction (XRD), and energy dispersive X-ray fluorescence (EDXRF) to determine their physical property, firing temperature, phase composition, and chemical composition, respectively. Results show that the firing temperature of body belongs to the temperature range (of 950–1,100°C), whereas the water absorption and apparent porosity are large. The phase composition of glazed tile bodies is the same (predominantly quartz and mullite). However, some samples contain trace amounts of rutile, hematite, sodalite, and orthoclase. The firing temperature combined with the phase composition indicates that the raw material and firing process of glazed tile body samples have similarities, which embody of the strict and unified management system of the official kiln. The raw materials of glazed tile body in the Ming Imperial Palace site may come from Dangtu glazed kiln, whereas the rest of the samples remains to be explored. This study provides a scientific basis for understanding the evolution of glazed tile-making technology in ancient China, and is important for the protection and repair of glazed buildings in the Ming Dynasty.     

Metallurgical study on some Sasanian silver coins in Sistan Museum

Elemental analyses and microstructural studies of historical metal artifacts provide researchers with invaluable and priceless information about metal extraction technology and the procedure of creating artifacts. In addition, the information is helpful for knowing about the metallurgical processes of the artifacts. This study was conducted by a microscopic examination and elemental analyses of seven Sasanian silver coins preserved in the Sistan Anthropology Museum, Iran. For the purpose of this study, three methods were employed: first, the proton induced X-ray emission microanalysis (micro-PIXE), to determine the main and trace elements of the coins; second, scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS), to perform elemental analysis to identify impurities of the metal; and third, microstructural analysis of the coins which was carried out with an optical microscope (OM). The elemental analyses identified Ca, Cu, Ag, Au, and Pb in the coins. The high quantity of Ag in samples validated the application of advanced and accurate cupellation technology for refining silver and separating impurities from raw ore. The gold concentration in the coins indicated the use of non-galena ore for silver extraction. Additionally, the microstructural analyses of samples pointed to the application of thermo-mechanical processes on coins.     

一批中国古代镶嵌玻璃珠化学成分的检测报告

结合外束质子激发X荧光（proton induced X-ray emission,PIXE）和能量色散X射线荧光（energy dispersive X-ray emission,EDXRF）分析技术,对中国新疆、湖北、四川、广东出土的古代镶嵌玻璃珠的化学成分进行了检测.结果表明：新疆拜城克孜尔墓地出土的西周-春秋时期镶嵌玻璃珠为CaO-MgO-SiO2玻璃,战国时期中国境内的PbO-BaO-SiO2和Na2O-CaO-SiO2镶嵌玻璃珠是同时存在的.本文亦对相关问题进行了一些讨论,并提出了部分今后的工作建议.     

深圳铁仔山古墓群出土铜器腐蚀情况研究

受深圳地区海洋气候及土壤环境影响,铁仔山古墓群出土铜器锈蚀情况严重。为了给后续的保护修复处理提供科学依据,需研究出土铜器锈蚀情况。为此,通过硝酸银定性分析、X射线荧光能谱分析、拉曼光谱分析等手段,对其表面锈蚀物进行综合分析。结果表明,该批铜器矿化严重,其锈蚀成分以孔雀石为主。其中一件铜器表面锈蚀物中含有氯磷钠铜矿,这在潮湿地区土壤环境出土的铜器中较为少见。此外,在另一件铜器表面锈蚀物中还发现疑似纳米SnO2成分。实验结果可对该批铜器的保护修复处理提供有力的理论依据和数据支持,并为深圳地区出土的其他青铜类文物的保护提供参考。     

Analysis of Heavy Metals in Smoke Deposits in the Limewash of the Royal Artillery Factory of Seville (17th Century): Contributions to the Location of the Furnaces

The Royal Artillery Factory of Seville in Spain originated from pre‐existing private bronze foundries dating from the 16th century. The paper analyses the stratigraphy of wall cladding in the areas traditionally known as the ‘Old Foundry’ and the ‘New Foundry’, through its characterization by optical microscopy, scanning electron microscopy with energy‐dispersive X‐ray spectrometry (SEM‐EDX), micro‐X‐ray fluorescence (μ‐XRF) and micro‐X‐ray diffraction (μ‐XRD), in order to analyse the metal deposits that have accumulated since the 17th century. The data obtained allowed the verification of the available historiographical information and the location of the original bronze smelting furnaces. The analysis of patinas deposited on the overlapping layers of lime also confirmed that neither the raw materials nor the composition of the alloys used presented any substantial changes.     

中国出土的一批战国古玻璃样品化学成分的检测

对化学成分体系的确定是中国古代玻璃研究中很重要的一个方面,为此,用外束质子激发X荧光技术(PIXE)、电感耦合等离子体原子发射光谱分析(ICP AES)等方法,对新疆、湖北、河南和重庆等地区出土的一批战国时期的玻璃珠(包含镶嵌玻璃珠)、玻璃璧样品进行了检测。结果表明,战国时期中国境内同时存在PbO BaOSiO2、K2O SiO2、Na2O CaO SiO2三种硅酸盐玻璃,分布的地域范围从中国的新疆东部一直到长江、黄河流域,以及南方的四川、贵州等地区。中国古代的PbO BaO SiO2和K2O SiO2玻璃在技术发展上应该具有密切联系。结合文献资料对这些玻璃的产地等相关问题进行了简要讨论。     

Quantitative EDXRF Studies of Obsidian Sources in Northern Hokkaido

Quantitative trace element data from six obsidian sources on the Japanese island of Hokkaido is presented. Previous work by Japanese scholars has utilized neutron activation analysis (NAA) focusing on the rare earth elements, or qualitative energy dispersive X-ray fluorescence (EDXRF). In this study, non-destructive EDXRF is used to generate trace element data for 9 elements. Bivariate plots of the incompatible trace elements (Ba, Rb, Sr, Y, and Zr) can be used to separate the obsidian sources in this study. Source separation was confirmed by using linear discriminant analysis. Stepwise discriminant analysis indicates that Ba, Sr, Rb, Ti, Y, and Zr are the most discriminating elements.     

探索明代鋄金熏炉的工艺

以无损的科学分析方法研究3件明宣德年制的鋄金熏炉,以解释明代时期的工艺特色。研究方法包括利用X射线荧光光谱仪和扫描电镜/能谱测定铁体和鋄金的成分,反射光显微镜深入观察铁器表面网纹坑的分布,密度和深度。以红外光谱仪检测得出熏炉的表面褐色涂料为传统的大漆。以探索当中3件熏炉工艺的异同,讨论技术上的改良变化为器物带来的好坏处。     

ANALYSING ARCHAEOLOGICAL BASALT USING NON‐DESTRUCTIVE ENERGY‐DISPERSIVE X‐RAY FLUORESCENCE (EDXRF): EFFECTS OF POST‐DEPOSITIONAL CHEMICAL WEATHERING AND SAMPLE SIZE ON ANALYTICAL PRECISION*

Energy‐dispersive X‐ray fluorescence (EDXRF) has been commonly used to determine geological sources of volcanic glass artefacts, but its ability to discriminate between basaltic sources is less developed. We examine the precision and accuracy of non‐destructive EDXRF for basalt artefacts by analysing varying size and weathering characteristics. The experiments identified no appreciable effect in reproducibility or measured composition due to thickness (down to 1 mm) or natural weathering of pre‐contact flake scars for the 17 elements measured in this study. Samples with surface area less than 100 mm², however, show significant variability in measured composition and reproducibility.     

广州增城墨依山玉器材质和受沁过程分析

为综合研究出土玉器的风化机理,正确评估玉器的保存状况,本研究采用物相、成分和电镜等方法对2016年广州重要考古发现——增城墨依山玉器进行了材质和结构分析,确认了墨依山玉器材质为透闪石。在此基础上,对玉器周边土壤进行了物相、成分、结构和酸碱度等分析,并结合玉器本体和遗址气候条件,综合探讨了强酸性环境下墨依山玉器的受沁过程。本研究有助于丰富对玉器风化机理的认识,有利于科学制定玉器的保护措施。     

上林湖越窑青瓷胎釉化学组成的EDXRF分析

为系统了解历代上林湖地区越窑青瓷胎釉化学组成的特点,本研究采用能量色散X射线荧光光谱技术(EDXRF),对唐代、五代、北宋和南宋上林湖越窑青瓷作了分析。分析结果表明,越窑胎釉组成是低铝高硅的南方青瓷特征,有一定量的杂质,历代瓷釉均为高钙釉;从唐代到南宋,越窑青瓷胎的化学组成未发生明显的变化,但唐代青瓷、北宋透明釉青瓷、南宋乳浊釉青瓷釉的化学组成存在一些差异;南宋越窑部分青瓷的外观虽然发生了变化,但釉料仍延续了越窑独特的工艺配方,与北方青瓷和南方官窑青瓷等的釉料差异明显。分析同时表明:该技术的使用为解决薄釉的样品处理难题提供了一条途径。     

Recent Research on Obsidian from Missouri Archaeological Sites

Obsidian has been noted at archaeological sites in the Midwest for over 160 years, although very few artifacts made from this material are recorded in archaeological contexts in Missouri. Background research revealed that only 16 obsidian artifacts from 13 sites had been documented from the state and that only 5 of the specimens had been geochemically analyzed and attributed to a source. Recent excavations at the Droste site (23PI1291), a Late Woodland period site in northeast Missouri, yielded two obsidian artifacts. The two specimens from the Droste site along with two previously unsourced obsidian artifacts from the Burkemper site (23LN104) and two from the Stapleton site (23HD110) were tested for trace element composition via X-ray fluorescence analysis. This article reports the results of these geochemical analyses, reviews the other obsidian artifacts reported from Missouri, and examines the cultural context and source of obsidian artifacts from other states in the upper Midwest.     

鸿山越墓出土战国玻璃的无损分析及相关认识

结合X射线衍射分析(XRD)、激光拉曼光谱分析(LRS)和便携式能量色散X射线荧光分析(P-XRF)技术,对鸿山越墓出土的战国玻璃进行了无损分析,根据化学成分分析结果将其划分为铅钡硅酸盐玻璃和钾钙硅酸盐玻璃两大体系。结合考古学研究结果,初步认为鸿山越墓出土玻璃可能与楚国有密切关系,是东周时期越楚之间文化交流的实物见证。