Bronze Artifacts Research Articles

Scientific examination and study of the Qijia culture bronze artifacts from Mogou site in Lintan, Gansu

Abstract The Mogou site in Lintan, Gansu, has yielded the largest collection of Qijia culture bronze artifacts discovered to date. More than 300 bronze artifacts were unearthed, including new forms such as bracelets, neck ornaments, and earrings with trumpet-shaped ends, reflecting the advanced bronze production technology during the late Qijia culture period. This paper presents an analysis of 146 bronze artifacts from the Mogou site, conducted through metallographic microscopy and SEM-EDS analysis. Our results indicate that a relatively high percentage of small ornaments, primarily made of tin bronze, underwent hot forging and cold working, while tools, primarily made of copper and tin-bronze, were typically cast. Furthermore, this study reveals the concurrent existence of leaded tin bronze and arsenical bronze during the late Qijia culture period, suggesting influences from multiple metallurgical systems.

In situ assembly of silver nanoparticles throughout electrospun oriented alginate nanofibers for hazardous rust trace detection on bronze

A convenient and reliable surface-enhanced Raman scattering (SERS) substrate has been developed for the surface corrosion analysis of bronze artifacts. The substrate consists of oriented alginate nanofiber membranes containing silver nanoparticles (Ag NPs), which were obtained through electrostatic spinning, ion exchange, and in-situ reduction. By controlling the reduction time, Ag/alginate nanofiber membranes with different contents, sizes, and distributions were obtained. The Ag/alginate nanofiber#20 membranes, obtained with a reduction time of 20 min, reached a detection limit of 10−12 M for R6G with an enhancement factor of 6.64 × 107. In the trace detection of bronze patina, the intensity of the characteristic peaks of harmful patina located at 513, 846, 911, and 974 cm−1 were increased by more than 500 %. This was due to the uniform loading of a large number of Ag NPs on the surface of the nanofiber membrane obtained by reduction for 20 min, and the formation of a large number of hot spots between the oriented nanofibers. This significantly improved the SERS performance of the flexible substrate layer under the joint action with the Ag NPs. These results indicate that the flexible substrate layer can greatly enhance the Raman characteristic peaks of alkali copper chloride and be effectively used for trace analysis of the surface composition of bronze artifacts.

Realisation and characterisation of Cu-based references for neutron imaging calibration purposes and first results

The long-term purpose of this study is to assess the capabilities of the new Neutron Imaging beamline developed at the LENA facility of Pavia (Italy) for the characterisation of bronze artefacts. In this preliminary work, a set of Cu-based reference alloys has been produced and analysed in order to test and calibrate the facility. The first step involved the production of Cu-based alloys with chemical composition and microstructure similar to ancient artefacts. The chemical composition of the reference alloys was analysed by Optical Emission Spectroscopy. Secondly, some samples were artificially patinated with different chemical treatments obtaining an artificial corrosion products layer comparable to natural corrosion. X-Ray Diffraction, Scanning Electron Microscopy and Raman Spectroscopy have been used to characterise the corrosion patina. The main corrosion products on sulphate-induced patina are cuprite and brochantite, whereas atacamite and clinoatacamite were detected on chloride-induced patinas. Finally, preliminary Neutron Imaging measurements were performed on a first set of coated and uncoated specimens in order to try to correlate the neutrons attenuation coefficients with the chemical compositions with promising results.

Jernlænken fra Fæsted

Jernlænken fra Fæsted

Extreme Sn isotope fractionation in highly evolved granites

Stable Sn isotopes have been widely used to trace the planetary differentiation processes, the provenance and trade paths of ancient bronze artifacts, the mineralization history of tin ore deposits, and the terrestrial magmatic processes. However, systematic Sn isotope studies of felsic igneous rocks especially the Sn mineralization-related highly evolved granites are still lacking. In this study, we present the first high-precision Sn isotope data of two Sn-rich highly evolved S-type granites (Laochang and Kafang) from the world-class Gejiu Sn ore district. These granite samples show remarkably variable δ122/118Sn values (relative to the Sn standard solution NIST 3161a) ranging from 0.11 ± 0.02‰ to 0.93 ± 0.02‰ (2σ), which is the largest variation range reported in granites so far. The absence of correlations between Sn isotopes and LOI (loss-on-ignition) and εNd(t) values, along with the low magmatic oxygen fugacity (△FMQ < 0) for these granites, rule out hydrothermal alteration, wall-rock assimilation, source composition heterogeneity, and anatexis processes as causes of the Sn isotope fractionation. The Laochang granites show negative correlations between δ122/118Sn values and magmatic differentiation indicators (e.g., CaO, Fe2O3, Ti, Eu/Eu*, F/Cl), suggesting fractional crystallization increased the δ122/118Sn isotopes in the residual melts. The fractional crystallized minerals are mainly composed of biotite, plagioclase, and minor ilmenite. Compared with the Laochang granites, the Kafang granites show higher SiO2 contents, F/Cl ratios, and δ122/118Sn values, suggesting the magma at this stage was fluid-saturated and fluid exsolution coupled with fractional crystallization would further enrich the heavy Sn isotopes in the residual melts. We further quantified the contributions of crystal fractionation and fluid exsolution on Sn isotopic variability using a Rayleigh fractionation model. The modeling indicates that △122/118Sncrystal-melt = −0.6 to −0.5‰ and △122/118Snfluid-melt = −1.9 to −0.7‰ with an initial H2O content of 2 wt.% can explain the observed δ122/118Sn values of Gejiu granites. This study implies that both crystal fractionation and fluid exsolution processes cause increase of Sn isotopic values in the highly evolved granites and Sn isotopes are useful for tracing the evolution of highly differentiated igneous rocks.

Quantitative analysis of copper alloys by means of portable X-ray fluorescence: A comparison between analysis of shavings and surfaces

The investigation of the alloy composition is a key point for studying archaeological and historical metal artefacts. Portable X-ray fluorescence is the most commonly used technique to perform non-invasive alloy analysis. Nevertheless, quantitative results are usually not reliable when metal surface is covered by either corrosion or patination layers. In such cases, micro samples, representative of the bulk alloy, have to be taken. Shavings samples are a good compromise between representativeness and degree of invasiveness when the purpose of the analysis is to obtain accurate quantitative data. This work aims at evaluating and comparing accuracy and precision of X-ray Fluorescence quantitative data obtained by performing analysis on the surface and on shavings of certified reference materials. Results point out that quantitative data obtained from surface and shavings samples have comparable accuracy and precision if a suitable calibration model using certified reference materials in the same form, i.e. surface or shavings, is applied. Repeatability tests were also carried out using the same certified reference materials. Results proved repeatable within 5% for all the detected elements. Uncertainties are slightly higher for shavings with respect to surface measurements. Two case studies concerning an archaeological and a Renaissance bronze artefacts are also discussed.

Lead isotope ratio analysis of lead ingots and bronze wares unearthed from Yinxu

AbstractThis study gives the element compositions and Pb isotope ratios of three lead ingots and three bronze artefacts unearthed from Yinxu, Anyang, Henan province, and two lead vessels from Zhengxiaozhuang tomb, Anhui province, China. The results of composition analysis show that three lead ingots in Yinxu may be the primary product of lead smelting. The lead wares unearthed in Zhengxiaozhuang tomb could be a kind of Mingqi‐funerary replicas. The results of Pb isotope analysis indicate that the culture exchanges between the Central Plains and the Jianghuai area in the late Shang dynasty. The decrease of bronzes with the highly radiogenic lead is consistent with the increase of Pb content in Yinxu bronzes simultaneously, which could be related to the change of lead source.

Scientific analysis of the bronze artifacts excavated from Xinfeng cemetery, Lintong district, Xi’an City, China: raw material sources determined by lead isotopes and trace elements

Scientific analysis of the bronze artifacts excavated from Xinfeng cemetery, Lintong district, Xi’an City, China: raw material sources determined by lead isotopes and trace elements

Design Ritual into Modern Product: A Case Study of Chinese Bronze Ware

Bronze wares make up some of the most important bronze artifacts in ancient China’s Xia, Shang and Western Zhou dynasties. They carry rich historical, cultural and artistic information. In order to enable modern people to reflect on the ancient through products, an important research topic that must be considered is how to carry out innovative designs with bronze ware and how to add value to the development of cultural creative industries so as to promote sustainable cultural development. This study puts forward a research framework for the innovative design of bronze ware. Based on analysis of relevant cases, such as a purple copper antique wine vessel, the “Qing Niao” (“Blue Bird”) asking love wine cup and the HIBIKI ware wine glass, the study summarizes the innovative design strategy of modern transformation design of bronze ware. From the perspectives of functional attributes, cultural symbols, cultural identity and emotional resonance, the study finally proposes three design ideas: antiqued design, simplified design and reconstructed design. The study presents a research model which still needs to be verified in future studies. We hope that the model can integrate the principles of sustainability into the modern transformation design of cultural relics.

The Fontanamare Discovery (Sardinia Coast, Italy), a Case of Underwater Corrosion of Bronze Coins

This study reports the analytical approach towards nine coins found in wreck A of Fontanamare for understanding the complex corrosion processes that take place in underwater conditions. Optical microscopy (OM) combined with micro-Raman (µ-Raman) spectroscopy, X-ray diffractometry (XRD), and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM and EDS) were used to analyze the nature and the microstructure of the corrosion patina in comparison with the non-degraded state of coins. Three main types of corrosion patina based on copper, lead chloride, and carbonate were identified: black, white, and green, and the obtained results demonstrate the complex corrosion processes that take place in underwater conditions. To better understand the role played by different chemical and physical parameters in the corrosion of bronze artefacts in an underwater environment, this study attempts to understand the nature of the patinas on the coins in relation to the specific structural and environmental parameter variation.

The rise of bronze in Central Asia: new evidence for the origin of Bronze Age tin and copper from multi-analytical research

The Bronze Age in Central Asia was dominated by the Andronovo Culture and the Bactria-Margiana Archaeological Complex (BMAC). Both cultural entities produced bronze, however, the extent of bronze production and use varied considerably in space and time across their territories. The introduction and spread of bronze metallurgy in the region is commonly associated with the Andronovo Culture, but comparatively little is known about the copper and tin sources that were exploited to make the bronze. To shed light on this aspect, this paper examines 91 bronze artefacts from the Middle Bronze Age (MBA) and the Late Bronze Age (LBA) recovered from twenty sites of Andronovo and the BMAC through a combined evaluation of chemical and isotopic analyses. Trace element patterns and isotopic compositions of lead, tin, and copper are determined for the objects complemented by tin isotope analysis of Central Asian tin ores. The data shows a clear separation of two source areas in the MBA and LBA I: the BMAC obtained copper from polymetallic (tin-bearing) deposits in Iran (Deh Hosein, Nakhlak/Bagh Gorogh) and possibly Afghanistan, while the Andronovo Culture mainly used copper from the Tian Shan Mountains. With the transition to the LBA II, a change in the material basis can be recognised, in which the BMAC increasingly relied on metal deposits from the Andronovo territory. The most important result in this context is the analytical proof of the coextraction of copper and tin from the copper-tin mine at Mushiston, Tajikistan, and the first direct link of tin in bronze objects with a tin deposit. Mushiston apparently supplied both cultural macro regions with a “natural” bronze, which accounted for about one third of all objects analysed, but there is no indication yet that metal or ores from Mushiston were traded or used at a distance of more than 500 km. Moreover, the artefact data indicates a decline in the exploitation of the mine in the course of the developed LBA, while other copper and tin sources in the Tian Shan and probably the Hindukush were exploited. This testifies to the intensive use of the rich mineral resources of Central Asia and beyond, as well as the intensification of cultural and trade contacts between Andronovo and the BMAC.

A study on ancient casting method via microstructures of impurities and copper found in bronze excavated from the Unified Silla Period (7th to 10th centuries)

At the Hwangnyongsa temple site, which was founded in 633, at Dongdaebong Mountain in Korea, a large number of gilt-bronze artefacts have been excavated. Optical microscopy, X-ray fluorescence, scanning electron microscopy, energy dispersive X-ray spectroscopy, focused ion beam and transmission electron microscopy were used to identify the structure of specimen and impurities. This article investigated the impurities and copper grains in bronze Buddha robes from the Hwangnyongsa temple site to determine the ancient bronze craft technology in the Unified Silla period (seventh–tenth). The XRF results of the specimens indicated that they were made using an alloy of copper and tin, and gold plating was only added on the front side. The microstructure of the specimen was confirmed to be a recrystallized equiaxed hexagonal structure with twins and impurities. The EDS results of the impurities indicated the molar ratio of Cu:S was 2:1, and the electron diffraction pattern substantiated this result by indicating Cu2S (JCPDF 33-0490). The surface of the specimen consisted of a highlead layer and copper grains. It was hypothesized that the copper grains were formed by the reaction of Pb with the matte (Cu2S) during casting. Lead with black gas would aid in the production of high-quality bronze. The copper grains used were found in Silla, as they have been detected in Koryo bronze artefacts. Hence, it is plausible that the ancient artisans knew that lead provided good bronze quality during the casting process.

Chemical analyses of Urartian bronze objects from the Ayanis fortress

The bronze finds from the Ayanis Fortress, dated to Rusa (son of Argishti) (680–640 BC), were analyzed by inductively coupled plasma mass spectrometry (ICP-MS) to investigate the alloying techniques of Urartian bronze work. The feasibility of a handheld portable X-ray fluorescence (pXRF) method for measuring the elemental characteristics of ancient bronze artifacts was also examined. The chemical data revealed that Ayanis bronze objects were made of copper-tin (Cu-Sn) alloy, but the Cu/Sn ratio varied for the artifacts, showing that tailored alloying techniques were not applied with regard to the function of the objects. Following a comparison of the elemental data from bulk and surface analysis, pXRF was deemed less accurate because of corrosion layers on the surface, even for mechanically cleaned samples. Microstructural observation showed features that imply several cold working and annealing cycles were applied during manufacture.

A new underwater laser cleaning tool for large bronze artefacts

A new underwater laser cleaning tool for large bronze artefacts

Microstructural Investigation of Some Bronze Artifacts Discovered in a Dacian Site Using Non-Destructive Methods

Dacian civilization flourished on the actual territory of Romania during the Late Iron Age and had its peak from the first century BC to the first century AD. They had intensive relations with Hellenistic and Roman civilizations. Therefore, it is difficult to evaluate the origin of some widely spread artifacts discovered in the Dacian archeological sites. The present research is focused on two bronze artifacts (a bronze coin and a mirror fragment) found in the Alun-Piatra Rosie site and a silver coin found in the Ardeu site. Artifacts were investigated with nondestructive methods such as SEM-EDX for microstructural and elemental characterization, and the crystalline phases were investigated using XRD. Bronze coin proves to be an Istrian issue having an elemental composition of 75.0% Cu, 20.8% Sn, and 4.1% Pb, which corresponds to a structure of Cu grains mixed with Cu5.6Sn grains. The bronze mirror fragment has an elemental composition of 52.3% Cu and 47.7% Sn, which corresponds to a structure containing grains of Cu6Sn5 mixed with grains of Cu41Sn11. It has a smooth surface that was investigated with AFM microscopy, which evidences a Ra roughness of 51 nm for the patina surface and 33.7 nm for the clean metal surface, proving the high quality of the original mirror luster of the artifact. The silver coin was identified as a Radulesti–Hunedoara type meaning that it was produced in local Dacian metallurgic workshops. It has an elemental composition of 63.1% Ag, 25.3% Sn, 7.8% Cu, and small traces of P and Fe, which corresponds to a structure of Ag grains and Ag3Sn grains. Silver coins show that Dacians uses Sn as alloying element in their metallurgic workshops. Istrian bronze coin proves to be typical for Hellenistic or Roman bronze type with Sn content no more than 25% Sn. The bronze mirror fragment has an unusual composition that might be a result of al local metal charge elaboration with several Hellenistic and Roman bronze pieces as raw material and an extra Sn addition during the melting process. This material facilitates the polishing properties of the active surface that has a very low roughness even after 2000 years of ground resting and adherent oxides patina.

Origin and Evolution of the Earliest Iron-Smelting Technologies in the Khakass-Minusinsk Basin

The Khakass-Minusinsk Basin is archaeologically one of the best studied regions of Russia. Bronze artifacts from the pre-Scythian and Scythian epoch from that area are famous worldwide. However, iron production appears rather late there. From 2009 to 2018, a joint Russian-Japanese expedition excavated several sites documenting the earliest iron manufacture in the Khakass-Minusinsk Basin. On the basis of these excavations and experiments, metallurgical technology was reconstructed. The results suggest an evolutionary model of metal production in the Khakass-Minusinsk Basin during the Xiongnu-Sarmatian period. Three types of iron-smelting furnaces are described, structurally differing in terms of air-blasting and slag removal. The conclusion is made that the initial iron production technology had been borrowed, and later evolved in situ.

On the Chronological Position of Siba Culture Metal Artifacts, Northwest China

This study shows that bronze artifacts typical of the Siba culture (Gansu, China), such as cast convex plaques with loops, open-gap hook earrings with trumpet-shaped ends, and lamellar stemmed daggers, are similar to those from burials of the Late Krotovo (Cherno-Ozerye) and Andronovo (Fedorovo) cultures in Western Siberia, while the socketed celt-adze from the Ganguya cemetery is paralleled by those from Late Krotovo, Alakul, and Srubnaya complexes. Open rings with two opposed cast trumpet-shaped ends, open-gap hook earrings with trumpet-shaped ends, and cast convex plaques with loops, as well as stemless lamellar bronze knives with triangular section along the entire length, synchronize Siba with the cultures such as Munkh-Khairkhan, Late Qijia, Lower Xiajiadian, and Late Glazkovo. Therefore, radiocarbon dates of the Siba culture are confi rmed, suggesting that it falls within the 1800–1400 BC interval. If so, Siba bronze knives with curved spines and I-beam-shaped section of handles, as well as cast convex plaques with loops, can be considered prototypes of Late Bronze Age types of the Karasuk and Irmen cultures. Populations of western China preserved earlier (Seima-Turbino?) traditions of metallurgy, having infl uenced the culture of the mountain-steppe zone of Northern Eurasia in the last third of the 2nd millenium BC.

Integration of Laboratory and Field Measurements on Soil and Bronze Artifacts: Facilitating Conservation Treatment and Management of Archaeological Collections

ABSTRACT Chloride ion, pH, and voltage (redox potential) measurements were conducted in the field and conservation laboratory on soil and copper alloy artifacts deriving from two archaeological sites of the Japanese Institute of Anatolian Archaeology, Kaman-Kalehöyük (Kırşehir) and Büklükale (Kirikkale), in Central Anatolia, Turkey. The project established the impact of the burial environmental conditions on the state of the recovered metal artifacts and applied this information to the subsequent conservation management of the metal artifacts in the collection. These measurements may be used to determine the degree of stability of the metal artifacts for their long-term preservation. Based on the test results a conservation plan may be drafted according to three options: (1) active conservation intervention (e.g., treating with a chemical corrosion inhibitor or desalination); (2) preventive conservation through control of the environment; and (3) no protective measures necessary. Recommendations for conservators include simple tests on soil and representative artifacts as a guide to predict decay behavior for post-excavation collection management. These test protocols may be applied to the interpretation of material degradation at all archaeological sites and may be adapted for other porous materials. A decision-making model is provided in a flow chart.

Helgö in the shadow of the dust veil 536-37

In this paper, the implications of the dust veil in 536-37 AD at the site Helgö in Lake Mälaren are investigated. One dramatic change at Helgö was the apparent abandonment around 530 of the Migration Period casting of bronze artefacts in Building group 3. A vast accumulation of casting moulds and crucibles was found here. The magnitude makes this context unique in northern Europe. Usually, the very fine-grained quarts sand used for the mould and crucibles was reused, and thus it would not accumulate. Anotherincident is that the open-air offering place, known to be in use already from the Later Roman Iron Age is abandoned. From this point, the cultic events are performed indoors in a large hall. Further, from this period onwards, the cemeteries on the site are commenced, indicating that the site now becomes permanently inhabited. Finally, although previously not known as a grave gift, bread is regularly found in graves.

Resolving the complex mixing history of ancient Chinese bronzes by Manifold Learning and a Bayesian Mixing Model

Provenance of metals is a major theme in Bronze Age archaeology since it can help to reveal complex cultural and economic entanglements in ancient times. However, where complex societies with diversified trading relationships are concerned, identifying metal provenance has often proved to be challenging due to the frequent mixing of metals from different sources in antiquity. This research addresses this question by developing an innovative method for interpreting lead isotope data of bronze artefacts. Manifold learning and a Bayesian mixing model are combined to reconstruct quantitatively the contribution of metal sources to ancient bronzes. The methodology is employed to resolve the complex metal circulation system in the Zhou period (11th-3rd century BC) of China, and reveals a significant diachronic change of metal resources from North, Central, and South China. The North China metal sources were mainly employed in the Early Western Zhou period (1046–950 BC). In the following ages, the Yangtze River Valley and Qinling Mountains became the major metal sources for Zhou people. The Middle Spring and Autumn period (660 BC-560 BC) witnessed a major shift of dependence between these two sources, demonstrating a fundamental transformation in the metal circulation system. The South China metal sources were exploited throughout the entire Zhou period and probably associated with polymetallic deposits in the Nanling area. This research reveals the long-term patterns of metal exploration and mixing in the Zhou period of China, and also demonstrates the great potential this new methodology promises in addressing the complex metal mixing history in other cultural contexts.