贵州银子坛墓地出土铜锡器的初步分析

为研究黔西地区铜器时代金属制作技术及水平,本文采用金相显微镜和扫描电镜,对贵州银子坛墓地出土13件铜器和2件锡器进行了金相观察和化学成分分析,发现中水银子坛墓地出土的战国到西汉时代的铜器,有红铜、锡青铜和铜锡铅合金多种材质,而锡器有纯锡器以及锡铅合金,合金配比已具有一定的水平。制作技术有铸造和锻造工艺,并能应用冷热加工技艺。本文对研究古夜郎地区金属器的制作技术有一定的价值。     

A Second Investigation into the Chemical Composition of the Roman Provincial (Procuratorial) Coinage of Judaea,AD 6–66*

An investigation of the chemical composition of the first Roman provincial coinage of Judaea, minted in ad 6–66, was conducted. A total of 103 copper‐alloy coins were analysed by ICP‐AES. It was determined that different copper alloys were used for the coinage, a leaded tin‐bronze and a pure tin‐bronze alloy. The investigation also showed that the copper alloy was made in four different formulae with regard to the alloying elements added to copper. Trace element profiles point to the existence of a shared pool of metal for Roman coins and metalwork.     

COPPER ALLOYS FROM THE ‘ENOT SHUNI CEMETERY AND THE ORIGINS OF BRONZE METALLURGY IN THE EB IV – MB II LEVANT

Tin bronze replaced arsenical copper as the preferred alloy in the Levant for reasons that have long been debated. Found almost exclusively in graves, these two types of copper alloys share nearly identical mechanical properties. The Bronze Age cemetery of ‘Enot Shuni has yielded the first metals ever analysed from an uninterrupted stratigraphic sequence in the Levant, spanning the earliest adoption of tin bronze from the Early Bronze Age (EB) IV through the Middle Bronze Age (MB) II (c. 2300–1530 bc ). SEM–EDS analysis of these artefacts, combined with a compositional meta‐database of all previously published EB IV – MB II alloys, reveals diachronic alloy progression as selected by populations of the Levant. It has long been qualitatively understood that bronze became the primary alloy by the MB II. These results verify this trend and quantify human demand, showing that tin importation increased by 103% and arsenic content decreased by 49% throughout these periods. This shift in technological choice is attributed to cultural reorientation from the Egyptian to Mesopotamian sphere of influence, as well as to tin's appreciable fuel efficiency over pure copper and arsenical copper in light of unprecedented timber shortages.     

SEM and electrochemical characterization of bronze artifacts from the Francavilla archaeological site

The excavations in the necropolis of the Francavilla Marittima archaeological area, in Calabria, have brought to light the rich burial artifacts and materials, dated between the end of the ninth and sixth centuries BCE. SEM/EDS analysis was conducted on some sections taken from a bronze artifact classifiable as an armilla or fibula fragment. Our aim was to elucidate the nature of the corrosion processes acting on the specimen. SEM investigation detected the segregation of tin towards the outer layer and a depletion of the copper content in the same region. Furthermore, the elemental distribution maps of the sections analyzed evidenced the presence of chloride ions in the border area between the corrosion patina and the metal alloy. Such anion migration of chloride ions into the interior of the alloy leads to a particular variant of the type of corrosion of structure that in the literature has been identified as structure I.A cavity electrode designed for electrochemical measurements of powders was used to perform cyclic voltammetry experiments devoted to explore the activity of the patina covering the surface of the bronze fragment. The surface layer consists mainly of tin and tin oxides; the layer immediately beneath it contains copper oxides. An increase of reactivity was shown in an acidic environment. The activity of the patina is greatly reduced at pH 5 and appears to be zero at neutral pH.     

Fuel Efficiency of Ancient Copper Alloys: Theoretical Melting Thermodynamics of Copper,Tin and Arsenical Copper and Timber Conservation in the Bronze Age Levant*

The melting of pure or alloyed copper, tin and arsenical copper ingots or recycled objects was a drain on the timber and dung fuel resources of many cultures. This paper suggests formulae grounded in thermodynamic principles in an attempt to estimate the energy requirements necessary to melt copper alloys common to both Old and New World cultures, with the goal of identifying consumption and conservation patterns. It has been suggested that tin bronze metallurgy was first adopted in the Levant during the Early Bronze Age (EB) IV, at the onset of the Late Holocene climate episode (c.2300–2000 bc ), becoming the most desired alloy by the Middle Bronze Age (MB) II (2000–1530 bc ) due to the ease of melting tin. To test this hypothesis, the formulae are applied here to all published Levantine EB IV – MB II copper alloys. Fuel conservation rates are proposed based on the thermodynamic formulae. Tin bronze is demonstrably more fuel efficient than pure copper. Due to the inherent difficulties in predicting the behaviour of arsenical copper compounds, it is suggested that melting experiments with representative alloys are conducted to further test and refine these energy relationships.     

Iron Age tin bronze metallurgy at Marlik,Northern Iran: an analytical investigation

The archaeological excavations performed in 1961 and 1962 at the necropolis of Marlik (Gilan District, northern Iran) revealed important archaeological remains dating to Iron Age I and II periods (late second/early first millennium BCE). While the metal collection from Marlik includes various gold, silver and bronze objects and is considered one of the most significant finds of metal objects from the prehistoric Iran, the technological investigations discussed in this paper provide information on tin bronze objects only from Marlik. Both the composition and the microstructure of 25 copper alloy objects have been determined in order to achieve a better understanding of the metallurgical processes used in northern Iran from the second to the first millennium BCE. Experimental analyses were carried out using inductively coupled plasma mass spectrometry (ICP-MS), scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDS) and optical microscopy. The results demonstrated that the copper-base objects were made of the binary copper–tin alloy with variable tin contents. Other elements such as As, Ni, Pb, Zn and Sb were detected in minor/trace amounts. Variable tin content may be due to the application of an uncontrolled procedure to produce bronze alloy (e.g. co-smelting or cementation). Microscopic observations and microanalyses revealed the presence of numerous copper sulphide inclusions, lead globules and intermetallic phases scattered in the bronze solid solution. The microstructures seen in the bronze objects under study were varied and included worked/annealed or dendritic grain structures.     

Technical Studies on the Bronze Age Metal Artefacts from the Graveyard of Deh Dumen,South‐Western Iran (Third Millennium BC)

During the excavations of the graveyard at the site of Deh Dumen in south‐western Iran, 15 graves from the Early/Middle Bronze Age were uncovered that contained a variety of metallic artefacts. This paper reports on the analysis of nine metal artefacts, including eight broken vessels and a decorative strip that covered the handle of a dagger. The ICP–MS results showed that the bodies of the vessels are made of tin bronze alloy with variable amounts of tin, while the internal piece of the base of one vessel is made from an arsenical copper alloy. Further, the metallic strip is a thin sheet manufactured with partially pure silver. Microanalytical and microstructural information yielded by SEM–EDS revealed elongated Cu–S inclusions and lead globules as various phases formed in bronze solid solution. This study presents some information about the transition from arsenical copper to bronze metallurgy in the third millennium bc in south‐western Iran.     

北周武帝孝陵出土铜器的焊接模拟实验研究

为研究出土铜器的焊接技术,但文献中仅有少量关于铜焊的记载,而且模拟实验研究少有进行,因此,进行了实验室焊接工艺的模拟研究。以北周武帝孝陵出土铜器中检测发现的焊料为依据,进行了相关的焊接模拟实验研究,并利用金相显微镜、扫描电子显微镜及X射线能谱分析仪分别对铜锡合金、纯锡焊接红铜样品进行了检测分析,结合结果的分析与讨论,排除了焊料为纯锡的可能性,进一步证实了孝陵发现的焊料为铜锡合金焊料。本研究开展的铜焊模拟实验为日后系统研究铜焊技术具有一定的参考与借鉴意义。     

LUSTRE COLOUR AND SHINE FROM THE OLLERIES XIQUES WORKSHOP IN PATERNA (SPAIN), 13TH CENTURY AD: NANOSTRUCTURE,CHEMICAL COMPOSITION AND ANNEALING CONDITIONS*

Lustre is a medieval ceramic decoration, corresponding to a nanostructured thin layer formed by metallic copper and silver nanocrystals embedded in a glass matrix, which required deep knowledge on the part of the artisans with regard to the raw materials used and the kiln conditions. Their empirical knowledge led to the achievement of colourful lustre decorations ranging from reddish to yellowish or even greenish, some of them with a metallic shine with an associated purplish iridescence. Lustre ceramics dating from the 13th century from the Olleries Xiques workshop in Paterna (Spain) have been studied, linking their chemical composition and nanostructure with their colours and shine. Two kinds of nanostructures are found, yellowish lustre decoration constituted by a silver metal–glass nanocomposite, and reddish lustre decoration constituted by metallic copper nanocrystals and copper oxide nanocrystals; in some cases, metallic copper nanocrystals covered with an oxidized shell of CuO and partly Cu₂O have been found. However, even with significant amounts of copper oxide, the lustre still exhibits a copper metal‐like shine. The bluish iridescence observed at a specular angle in the lustre could not be explained completely by means of the chemical composition, and metallic silver nanoparticle light scattering is proposed as a possible explanation.     

ROMANO‐EGYPTIAN RED LEAD PIGMENT: A SUBSIDIARY COMMODITY OF SPANISH SILVER MINING AND REFINEMENT*

Samples of red pigment from a group of seven Roman‐period Egyptian mummies, known as red‐shroud mummies, are investigated. Elemental analysis by inductively coupled plasma time‐of‐flight mass spectrometry (ICP–TOFMS) shows that the samples contain mostly Pb (83–92% by weight), along with 0.2–2.0% Sn. All of the samples are found to have similar trace element distributions when normalized to the continental crust, suggesting that they share a common geological origin. Lead isotope ratios are found to match the mixed lead sources typically associated with Rio Tinto, Spain – a site extensively mined for silver during the first century ad . Raman microspectroscopy identifies the major phase of each sample to be red lead (Pb₃O₄) with a minor phase of lead tin oxide (Pb₂SnO₄). Lead tin oxide does not occur naturally, and its incidental occurrence within the sample indicates that the material was heated under oxidative conditions at temperatures in excess of 650°C. In archaeological contexts, the high‐temperature oxidative treatment of lead is typically associated with metallurgical refinement processes such as cupellation. Based on this evidence, it is argued that the pigment was produced out of litharge associated with silver cupellation at the Rio Tinto site.     

云南祥云县检村石棺墓出土铜器的初步研究

为研究滇西地区青铜文化及相关铜器的制作技术,本研究采用扫描电镜和金相分析的方法,对云南祥云检村石棺墓出土的17件样品进行取样分析,结果表明祥云检村石棺墓出土的铜器以红铜为主,少数为Cu-Sn合金。这些器物的制作工艺主要是铸造、铸后冷加工等,制作工艺相对单一。3件编钟均为Cu-Sn合金,并且锡成分具有等比递增的现象。兵器矛经过鉴定后说明由于墓主身份的不同,随葬的矛也有实用器和随葬器两类。农具锸和工具锥和凿的鉴定表明有冷加工或使用过的痕迹,可能曾是实用器;而农具锄经鉴定并没有在农作中使用过,仅作为随葬品,进一步证明随葬铜锄是青铜时代滇西地区的一种丧葬习俗。分析表明,当时已根据不同器物的用途进行了不同的制作和加工。本研究结果对研究滇西青铜文化及金属技术有一定的意义。     

成都市博物院几件院藏青铜兵器的分析研究

为了解巴蜀青铜兵器的制作技术及表面斑纹形成机理,采用金相显微镜分析,扫描电镜及能谱仪对成都市博物院的几件带斑纹的馆藏青铜兵器进行了分析。结果表明,两件截面样品均为青铜铸造组织,锡含量平均为11％。三件器物表面斑纹层均含锡和铜并具有一定抗氧化作用。斑纹工艺可分为二类：剑周99-1极可能为直接铸出凸凹不平的剑体,在凸起部位涂高锡合金膏剂,加热处理后得到。另一类可能先直接铸出金属基体,在欲成斑处涂抹合金膏剂或纯锡,加热处理打磨得到。分析结果可为深入研究巴蜀青铜兵器提供参考。     

荥阳小胡村墓地出土部分铜器的科学分析

小胡村墓地为殷墟晚期"舌"氏家族墓地,为探讨其出土铜器的腐蚀特征,揭示其所蕴含制作技术和相应考古学信息,从而为器物保护修复提供科学依据,采用金相显微镜和扫描电镜及能谱仪对墓地出土12件铜器进行基体锈层结构和制作技术分析研究。研究表明,相较纯铜、铜锡和铜锡铅合金,铜铅合金耐腐蚀能力较弱,腐蚀严重;铜器经冷热加工处理易造成内部组织结构不均内应力残存,间接加速铜器腐蚀;12件铜器材质:纯铜2件、铜铅合金4件、铜锡合金3件和铜锡铅合金3件;仅2件兵器(刀M28:1、戈M38:1)经有意铸后热锻和冷加工,其余皆直接铸造成型。M21墓4件铜器皆为铜铅合金明器,小胡村墓地作为殷墟周边商文化系统,趋同商文化中心区,亦呈现部分中小贵族随葬铜器明器化现象。研究结果可为器物修复保护提供科学依据。     

Early Cambodian gold and silver from Prohear: composition,trace elements and gilding

Rescue excavations in Prohear, southeast Cambodia, recently saved the last untouched graves of one of the richest prehistoric sites in Southeast Asia. Many Iron Age burials dating from the 2nd century BC to the 1st century AD contained gold and silver ornaments so far unknown from archaeological contexts together with indications for the presence of an immigrated elite. A first selection of 59 objects were analysed by LA-ICP-MS to obtain detailed information about the composition, as well as minor and trace elements. The majority of the ornaments consist of electrum and auriferous silver with low copper concentrations, and two main groups indicating different alluvial gold sources can be distinguished by different concentrations of Pt, Ir, Bi and different Pd/Pt ratios, one group being related to rich burials with non-local features. The SEM and EDX analyses of four objects revealed two different gilding techniques observed for the first time in Southeast Asian artefacts: foil-fusion gilding, related to special Ag–Au–(Cu)–Sn alloys containing up to 4% tin, and depletion gilding.     

QUANTITATIVE ANALYSIS OF COPPER-TIN BRONZES BY MEANS OF GLOW DISCHARGE OPTICAL EMISSION SPECTROMETRY

Glow discharge optical emission spectrometry (GDOES) has been used for obtaining calibration curves for copper, tin, lead, silver, antimony, arsenic, zinc and iron from standards including copper-base alloys (Cu 61.33-99.95%) and from bronze Punic coins. The GDOES results were calibrated using atomic absorption spectroscopy with inductively coupled plasma atomization (ICPAAS) to analyse the standards and coins. For all these materials, the results show that via GDOES it is possible to obtain reliable and reproducible calibration curves for copper, tin, lead, zinc and iron with a linear behaviour as a function of the content. The quantitative GDOES and ICPAAS data for the coins have been also compared with those obtained via X-ray fluorescence (XRF) and it is shown that GDOES, ICPAAS and XRF agree well with one another considering that the bronze coins are inhomogeneous to some degree. As an example of GDOES analytical features, a depth concentration profile through a thin bronze patina is shown and briefly discussed.     

THE BLACK INLAY DECORATION ON A MYCENAEAN BRONZE DAGGER*

The black inlay decoration with superb marine, hunting and other scenes on Mycenaean bronze daggers and silver cups has often been referred to in the literature as niello—a mixture of sulphides of copper, silver or lead—despite the absence of any systematic analysis of these precious metal artefacts. This paper presents semi-quantitative surface analyses of an example of black inlay on a Mycenaean dagger, now in the Archaeological Museum at Patras in Greece. Using non-destructive X-ray fluorescence spectrometry, it has been established that, contrary to the traditionally-held view, the black inlay is a copper-gold alloy with some silver and possibly small amounts of tin.     

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.     

云南昆明石寨山出土汉代青铜器的初步分析

云南昆明的石寨山墓葬是汉代滇池区域的土著文化,为了了解该地汉代铜器的制作工艺水平,本研究通过金相显微镜观察、扫描电镜及能谱分析的现代分析手段来对M3、M5、M6、M7、M10、M12这6个墓葬群的31件青铜器展开探讨。结果显示在31件铜器样品中,有30件为铜锡合金,1件为红铜,所有器物均为铸造,其中有1件铜戈的刃部经历过热锻加工。这一分析结果丰富了石寨山文化的铜器研究,为器物的保护修复提供科学依据,同时也为云南汉代时期的铜器考古学以及金属技术史补充部分资料。     

Late medieval copper alloying practices: a view from a Parisian workshop of the 14th century AD

161 late medieval copper-based day-to-day items have been analysed, mostly consisting of small artefacts such as dress fittings. The items were all recently excavated from a 14th century AD metallurgical workshop located in Paris. Eight well-defined copper alloys have been identified that refer to various constraints, the most important one being economics. According to the model proposed, most of the alloys were obtained by dilution of a fresh brass master alloy by scrap metal containing small amounts of zinc, tin and lead. Pure lead was added separately in relatively large quantities, with a limit of 6 wt% Pb marking the boundary between leaded and unleaded alloys. It has been found that the less the cost of the artefact, the more the fresh brass is diluted. For the medium-size castings such as cast vessels, alloys containing large quantities of lead or alloys rich in antimony were used. Such complex alloying strategy pertains more to a small industrial-like plant organisation rather than to craftsman activity, as further supported by a variety of archaeological and historical evidence.     

GOLD AND SILVER ALLOY COATINGS OVER COPPER: AN EXAMINATION OF SOME ARTEFACTS FROM ECUADOR AND COLOMBIA

An examination, by metallography, atomic absorption spectrophotometry, and electron probe microanalysis of some decorative metalwork and small items such as needles and fish-hooks from Ecuador and Colombia revealed that ‘fusion-gilding’ or ‘wash-gilding’ was employed in the manufacture of many artefacts. The coatings found included silver alloy coatings over copper and gold alloys over copper. The coatings are often themselves superficially enriched at the surface; they are thick, and completely different from the surfaces found on depletion gilded objects which are far more common in ancient Colombia. The evidence from Ecuador is piecemeal and a considerable number of additional analyses must be carried out to clarify the extent of use of this surface treatment technology.