Ancient Metal Research Articles

‘I heard about the negotiation with Agostini’

Abstract This article focuses on negotiations that took place between 1667 and 1673 leading to the purchase by Prince-Cardinal Leopoldo de’ Medici (1617–1675) of the bulk of the collections assembled by the antiquary Leonardo Agostini (1593–1676). This was one of the most important acquisitions by the Medici family in the second half of the seventeenth century, and it brought different types of objects into the grand-ducal collections: medals, intaglios, cameos and ancient metal objects. Several go-betweens and experts were involved, the most important being the antiquary Ottavio Falconieri (1636–1675), Leopoldo’s agent in Rome. Recently discovered letters exchanged between Leopoldo and Falconieri shed crucial new light on the whole story.

Feasibility Examination of the Field Multi-focal Metallography Method (FMM) for Characterisation of Metallic Marine Artefacts

Field multi-focal metallography (FMM) is a development of field metallographic replication (FMR). It is an innovative minimally destructive technique that facilitates high-resolution metallographic observations of metallic object surfaces, regardless of their orientation to the optical axis of the microscope. Several artefacts retrieved during underwater excavations (a bronze powder chamber, a stud-link anchor chain, a winch, a heart-shaped shackle, a deadeye strap with a futtock plate, and an iron stud-link chain controller) were examined. The FMM results were compared with conventional metallography, where the sampling process inflicts substantial damage to the item. This FMM trial produced results of comparable quality to conventional metallography for both the bronze and the ferrous objects. It revealed the microstructure of the archaeological objects with minimal damage. The FMM method was shown to be a suitable tool for the study of ancient metal objects retrieved from shipwrecks.

Metals in Heritage Science

The valorization of our Cultural Heritage is deeply grounded in the study of the production, use and consumption of ancient metals [...]

The Ancient Metal Miners of Vadnagar, Delwara and Mandli, Western India

Abstract India is dotted with myriads of ancient metal mines or old workings in almost all the states, some of which have great antiquity (>4,000 yrs) and reaching considerable depth (upto 260 m). These stand as testimony to the mining skill of our ancestors, especially in the absence of mining tools. Several of these old metal mines, when explored by modern methods have yielded sizable deposits e.g. Hutti, Bhukia (gold), Rajpura-Dariba (multi-metal), Agucha (lead-zinc-silver), Agnigundala (lead-copper), Khetri (copper), etc. A few ancient Indian treatises describe the processes of metal extraction from the ores but records are scanty on the methods of mining and mining communities. Most experts consider that, the history of mining in India is obscured in the mist of antiquity and opine that ‘we lack the knowledge of old miners of India, as to who they were, from where they came or what was their fate’. The trailblazers though did not leave direct records nevertheless the opportunity is not closed to reconstruct missing pages related to ancient metal miners in the history of mining in India. An attempt has been made in this paper to bring out details of these miners based on comprehensive study and analysis of archaeological, geological, ancient metallurgical, historical, etymological and modern age data in conjunction with locals in the field, especially on those who were active in mining in border areas of present Gujarat, Madhya Pradesh and Rajasthan in western India. It resulted in establishing the people of Vadnagar, Delwara and Mandli localities as expert miners, who were responsible for opening and operating a large number of mines in the region viz. Ambaji, Bhukia, Delwara, Khandia, Zawar, etc. Archaeological evidences and radiocarbon dates attest to a Chalcolithic to pre-historical period of some of these old mines. Nomenclature of some gold bearing rivers and gold mining localities in the country displaying Vedic gold names speaks for their antiquity. Mauryans (321-185 BC) accelerated metal mining in their empire, which was followed by other dynasties till Rajputs who were assisted by tribal Bhils. The knowhow of ancient metal miners of Vadnagar, Delwara and Mandli seems to have descended from Mahabharata and Harappan tradition of Gujarat (3950-900 BC) and Ahar-Banas (3600-1800 BC) culture of Rajasthan. During Mughal invasions many miners and metal workers had migrated to remote Himalayan areas (present Himachal Pradesh, Uttarakhand) or Hindu kingdoms (present Maharashtra, Odisha) where they adopted nomenclature of their place of origin (Vadnagar, Delwara and Mandli) to their new settlements. Some of these experts took-up mining profession while others developed expertise as blacksmiths/ whitesmiths or even agriculturists. Zinc coins of Kangra (14th Century AD) kings seem to have produced by these migrating metal experts who knew the technique of zinc distillation from ore of Zawar mines, the people of which are considered as first to smelt Industrial zinc in the world.

The Most Ancient Metal Spearheads in Eastern Europe (on Reconstructing the Indo-European Weaponry Complex)

The Most Ancient Metal Spearheads in Eastern Europe (on Reconstructing the Indo-European Weaponry Complex)

Improved Utilization of Radiographs of Ancient Metal Objects under Heterogeneous Image Blurring

ABSTRACT Availability of pertinent and detailed information for damaged ancient objects is vital for successful restorative, damage limitation intervention processes in archeology. Visual inspection and radiography testing (RT) constitute widely used non-destructive methods for conservators of such objects. Unfortunately, the quality of RT images is susceptible to blurring caused by the superimposed scattered X-rays. In this study, the no-black-pixel constraint (NBPC) algorithm on its own as well as in the form of an algorithm with the planar-scene assumption (NBPC + PA) was applied to RT images with a view to suppressing image blurring and enhancement of imaging contrast. The results of this study have shown, both qualitatively and quantitatively that the NBPC + PA and NBPC algorithms provide higher imaging contrast for identification and evaluation of damage in corroded ancient metallic relics than using unprocessed RT images alone. Contrast enhancement of up to about 120% and 78% was achieved in comparison with the original image by applying the NBPC+PA and NBPC algorithms, respectively. Practical application and effectiveness of using the processed images were evaluated by expert operators in the area and it was found that using the reconstructed images scored higher (on average by 88%) than the original RT images (on average by 73%) with the NBPC+PA scoring higher (on average by 91%) than the NBPC algorithm (on average by 85%). The operators have found utilizing the processed images leads to better inspection and evaluation of the object enabling better targeted informed for restorative intervention, damage limitation, and maintenance of such objects.

REFLECTIONS ABOUT THE CRAFTSMANSHIP OF MAKING IRON AND STEEL WEAPONS IN GEORGIA

Metallurgy has always played an important role in the almost 4000-year history of Georgia's statehood. Its specificity, development, ups and downs and new reincarnations in other times and places, over and over again, is the main plot of this article. The metallurgical centers of South Georgia (the Lower Caucasus Range) are considered the birthplace of iron metallurgy in the world and throughout the ancient era played a leading role in the markets of the then world. However, during the Middle Ages, Georgian metallurgy was forced to hide in the Northern Mountains to keep away from aggressive invaders, and suffered from a limited ore base and isolation. The article attempts to analyze and clarify iron deposits in Georgia, which may have been used by ancient metal masters. In addition, those small elements were established that were added to iron to produce high-quality steel, and later Damascus steel in Georgia.

Combining isotope ratios for provenancing Viking Age iron artefacts in the British Isles: a pilot study.

Stable and radiogenic isotope analysis - particularly using lead isotope analysis (LIA) - has previously been shown to be a useful tool for the provenancing of ancient metal artefacts of silver and copper and its alloys, but less progress has been made in the provenancing of iron artefacts, despite their importance and frequency in the archaeological record. In this pilot study we investigate for the first time the possibilities of iron isotope analysis in combination with trace strontium isotope analysis and LIA for the provenancing of iron objects believed to be from the Viking Age in the British Isles. Previous studies have shown that analysis of each of these isotopes can contribute to provenancing iron artefacts, but they are not individually resolutory. In this proof-of-concept study, we examine the Fe, Sr and Pb isotopes of 7 artefacts believed to derive from the Viking Age: 3 from Meols - a former Viking seaport on Wirral and 4 samples from the probable location of the AD 1066 Battle of Fulford in North Yorkshire. We also examine an additional artefact of unknown antiquity from Bebington Heath - a possible location of the AD 937 Battle of Brunanburh. Although the pilot data set is too small to make definitive conclusions, it has paved the way for a fuller study involving 100 samples (including 30 from the former Viking camp of Torksey, Lincolnshire) funded by the NEIF fund of the UK National Environmental Research Council. The high range of 87Sr/86Sr values in the present data set of 8 is beyond what would be expected for bog iron (with a cut-off ∼ 0.709) and suggests that mined ore was being used, a preliminary conclusion supported by the narrow range of Fe isotope data.

Deposition of Base Ore and Alloy Elements in the Bronze Age Metal in the Trans-Urals

The paper studies the problems of the geochemical specialization of the Bronze Age metal items from the eastern flank of the Ural mining and metallurgical province produced at the end of the third millennium BC — the middle of the second millennium BC in the Abashevo, Sintashta, Koptyakov-Seimino and the Alakul centers. The metal geochemical markers determination was performed by means of a local quantitative chemical composition analysis of 101 solid samples with an electron X-ray microanalyzer. The selection consisted of a representative series of copper and bronze items corresponding to various stages of metallurgical conversion process from the classic archaeological sites of the Trans-Urals. Systematization of the analytical data on the chemistry of items from each metal production center made it possible to identify stable compositions of micro-impurities associated with the base ores and alloys. The Abashevo and the Sintashta culture metal demonstrated a stable correlation of excess arsenic and nickel concentrations, which was partly due to the use of the Trans-Urals ores with a high content of these elements, however, the most significant concentration of arsenic (from 2 to 5 %) was observed in the finished items rather than in refined copper ingots or semi-finished products, which may indicate intentional alloying. Tin alloys in the Sintashta culture were quite rare; they demonstrated the same chemistry as the Seimin-Turbino metallurgical traditions. Large-scale use of tin for refined copper alloying was observed only in the Koptyakov-Seimino and the Alakul series. The Alakul series contained some high-tin alloying compositions close to the ideal tin bronzes (18 % Sn). It is possible that the sources of tin for them were the Kazakhstan and the Central Asia deposits. The only impurity integrating the entire ancient metal series, according to microprobe analysis, was sulfur, due to the sulfide feed stock. Sulfur was deposited in blister from the high-copper (above 20 % Cu) sulfide-silica-carbonate mineral blends that met the Bronze Age metal production criteria. The sources of raw materials were associated with the secondary sulfides of the ophiolite deposits hypergenesis zones in the Trans-Urals.

Transmission and innovation on gold granulation: the application of tin for soldering techniques in ancient China

Granulation, an ancient metal processing technique mainly applied to gold, has originated from West Asia, and later appeared at many different archaeological sites across the Eurasia. The distribution of granulated gold ornaments bearing diverse soldering techniques reveal the long-distance human interaction across the Eurasia. This paper presents the scientific analysis of the surface morphology and elemental composition of two granulated gold ornaments from Tushan Tomb No.2 pit in Xuzhou, Jiangsu Province, which approximately dated to the first century CE of Han Dynasty. Multiple non-destructive analytical methods including Ultra-Depth Three-Dimensional Microscope, Energy dispersive X-ray fluorescence spectrometer (XRF) and Scanning electron microscope with energy dispersive X-Ray spectrometer (SEM-EDS) were conducted to obtain analytical data. The result indicates that tin-participated soldering technique has been adopted to accomplish the granulation. Although the usage of tin has been mentioned in a former study as “a secret of Etruscan granulation”, the lack of quantitative analyses leaves this assumption unconvinced. Our findings on Tushan ornaments throw light on this issue by illustrating the regular distribution pattern of the tin content at the joints, which appears to be intentionally added for certain amount. Although tiny in size, the gold granules record the secret of soldering techniques used in China and many other regions across the Eurasia during the ancient time, complementing the study of granulation techniques and reflecting the transmission and innovation along with the technological and cultural contacts.

Rationally engineering a hierarchical porous carbon and reduced graphene oxide supported magnetite composite with boosted lithium-ion storage performances

Ferric gallate (Fe-GA), an ancient metal–organic framework (MOF) material, has been recently employed as an eco-friendly and cost-effective precursor sample to synthesize a porous carbon confined nano-iron composite (Fe/RPC), and the Fe element in the Fe/RPC sample could be further oxidized to Fe3O4 nanocrystals in a 180 °C hydrothermal condition. On this foundation, this work reports an optimized approach to engineering a hierarchical one-dimensional porous carbon and two-dimensional reduced graphene oxide (RGO) supporting framework with Fe3O4 nanoparticles well dispersed. Under mild hydrothermal condition, the redox reaction between metal iron atoms from Fe/RPC and surface functional radicals from few-layered graphene oxide sheets (GO) is triggered. As a result, reinforced microstructure and improved atomic efficiency have been achieved for the Fe3O4@RPC/RGO sample. The homogeneously dispersed Fe3O4 nanoparticles with controlled size are anchored on the surface of the larger sized RGO coating layers while the smaller sized RPC domains are embedded between the RGO sheets as spacer. Challenges including spontaneous aggregation of RPC, over exposure of Fe3O4 nanoparticles and excessive restacking of RGO have been significantly inhibited. Furthermore, micro-sized carbon fiber (CF) is chosen as a structural reinforcement additive during electrode fabrication, and the Fe3O4@RPC/RGO sample delivers a good specific capacity of 1170.5 mAh·g−1 under a current rate of 1000 mA·g−1 for 500 cycles in the half cell form. The reasons for superior electrochemical behaviors have been revealed and the lithium-ion storage performances of the Fe3O4@RPC/RGO sample in the full cell form have been preliminarily investigated.

Non‐invasive surface analysis of ancient bronze arrowheads with scanning electron microscopy and X‐ray powder diffractometry

In this research, surfaces of eight ancient metal arrowheads were investigated regarding chemical composition, homogeneity, and products of corrosion. To perform that, two nondestructive techniques were applied: Scanning electron microscopy coupled with energy dispersive spectroscopy (SEM‐EDS), and X‐ray powder diffractometry (XRPD). Importantly, both methods did not require sampling, cutting, nor significant cleaning of the historical artifacts, which made the measurements not only nondestructive but noninvasive too. SEM‐EDS measurements provided information on the morphology and elemental composition of the surfaces of the studied objects as well as the distribution of chemical elements on the surfaces and supported crystalline phase analysis. It was revealed that the arrowheads were cast of tin bronze, but some of them contained high amounts of lead and admixtures of antimony and arsenic while copper and tin oxides and lead carbonates were found as the major corrosion products. In some cases, distribution of elements in the surface exhibited serious nonhomogeneity, probably resulting from limited solubility of the casting metals and degradation processes. Based on the obtained results, authenticity and declared provenience of the arrowheads were assessed in reference to the characteristics of similar objects described in literature.

Innovative nano silicone wax coatings for the conservation of bronze artifacts from corrosion

Herein we studied the efficiency of a protective transparent and reversible nano silicone wax coatings (NSW) to protect bronze artifacts extracted from Herakleon City, Abu Kir Bay, Alexandria, Egypt. The nano structured silicone wax film resulted in the formation of a structure that can act as a barrier layer from corrosion. The application of NSW coatings on bronze artifacts was evaluated by electrochemical impedance spectroscopy and scanning electron microscopy techniques. Exposure of bronze samples with and without the nano silicone wax coating to sodium chloride solution led to a remarkable inhibition of corrosion for the coated samples only. Comparison of the inhibition efficiency obtained from samples coated with nano silicone wax coatings to that obtained from silicone wax coatings in normal size revealed that the protection efficiency is very high in case of nano silicone wax coatings compared to the traditional silicone wax coatings. The application of nano silicone wax coatings on bronze artifacts can pave the way into the development of safe and tailored solutions in the field of ancient metal artifacts conservation.Graphical abstract

Water quality and risk assessment of copper content in drinking water stored in copper container

In most developing countries, drinking water is still a serious challenge. Many water purification methods exist, but they are costly and out of reach for many people. Copper is an ancient metal that has been used from several thousands of years. Because of its antibacterial properties, ancient cultures held this metal in high regard. Copper vessels are still in use today for storing drinking water due to its ability to purify water. Therefore, the objective of this study was to evaluate the copper concentration in drinking water after storing in copper containers/bottle over different time periods with respect to copper safety levels. For this study, water is stored in a copper container up to 168 h and the water samples are collected at different intervals. The concentration of copper is analyzed in water samples using ICPMS, and it ranges from 0.009 to 0.823 mg/L, which indicates as time increases simultaneously copper content also raises in the stored water. The higher copper content was detected at sample@168 h which was also well within the permissible limits of World Health Organization and United States Environmental Protection Agency.

DONETSK MINING AND METALLURGICAL CENTER AND PRODUCTION HUBS OF THE EASTERN EUROPEAN STEPPE OF THE BRONZE AGE: A COMPARATIVE ANALYSIS OF PRODUCTION ACTIVITIES

Large-scale works have been carried out at the beginning of this century on the background of the set of Bronze Age monuments in the zone of Kartamysh copper ore occurrence in the Bakhmut basin of Donbass. Taking into account some previously researched monuments of mining and metallurgical activities within other ore occurrences of the Donetsk ridge, those works enable to compare the monuments of the Donetsk Mining and Metallurgical Center (DMMC) with other specialized monuments of Srubnaya cultural community in the copper ore territories of the Eastern European steppe.
 The monuments of Kartamysh archaeological microdistrict, as well as the other monuments of the Donetsk mining and metallurgical center, located in the zone of copper ore occurrences in the Bakhmut basin of Donbass, give evidences of all the cycles of ancient metal production. The majority of them are the evidence of the mining and ore-dressing cycle. Thus, the considerable volumes of mined and dressed ore, found in Kartamysh, as well as in other ore occurrences of the Bakhmut basin, currently suggest that the monuments in the ore territory of Donbass mainly operate within mining system. Similar specialization is observed in other mining and metallurgical areas in Eastern Europe, such as Mikhailo-Ovsyanka (Povolzhye) and Kargaly (South Ural). A feature of the DMMC is far lesser intensity of metallurgy and metalworking in its cultural frames. Limited range of DMMC monuments indicate that the production of metal products was focused only on domestic consumption.
 Fracturing of the Donbass bedrock, in contrast to the monolithic bedrock of Povolzhye, and especially to the Southern Urals, facilitated the effective use of stone tools in the process of mining. In the MMC, operating within the eastern production zone of the Srubnaya cultural community (Mikhailo-Ovsyanka, Kargaly), miners and metallurgists had to develop metallurgy more actively, since the features of geology in these regions required the use of metal tools to extract copper ores. Obviously, this circumstance explains a large number of end fragments of metal pickaxes found at Kargaly, as well as casting molds for casting these tools.
 The functioning of the full-scale cycle of ancient metal production and even visually recorded scale of ancient mining activity in the zone of copper ore occurrences of the Bakhmut basin gives reasons to assert the existence of mining and metallurgical center focused on large-scale production in the Donetsk Ridge in the Bronze Age. The main products of the DMMC were not metal items or even ingots, as it had been considered previously, but enriched copper ore (concentrate) as raw material for metallurgical production.
 Enriched ore was the commodity to be exchanged by the miners and metallurgists of the Donetsk center. It could be possibly done via professional traders with neighboring and distant tribes, and was exchanged for livestock and agriculture products, as well as for various household items.
 The analysis, carried out in the paper, proves that other mining and metallurgical complexes of the Eastern European steppe (Kargaly, Mikhailo-Ovsyanka), which had been previously explored, also operated at the same time and in similar to the DMMC production system.

Long-Term Embrittlement of Ancient Copper and Silver Alloys

The manifestations of ancient metals’ embrittlement, cracking and fracture, are challenging problems for restorers and conservators, yet the scientific understanding of these problems is limited. In particular, the study and interpretation of fracture surfaces, fractography, is a minor or non-existent consideration for most archaeometallurgical investigations. This paper presents a survey of fractographic analyses, in combination with the more widely used disciplines of microstructural studies, metallography, and chemical analyses for some Old-World copper alloy (bronzes) and high-silver alloy artifacts that have undergone long-term corrosion and embrittlement damage. We show that fractography, as an adjunct to metallography, can improve the interpretation of these types of damage and assist in selecting the best methods for restoration and conservation of the objects made from these alloys.

Investigation of elemental composition of ancient metal objects found in Khorasan-e Razavi Province of Iran using micro-PIXE technique

In this work, elemental composition of 18 metallic objects belonging to the Bronze Age found at the Kalate Shoori site in Neyshabur, northeastern Iran, is investigated using micro-PIXE technique. The aim of the analysis is to identify the type of alloys employed in the fabrication of the investigated objects based on their elemental composition and to measure their contents of trace elements. The results of the micro-PIXE analyses indicate that the investigated objects could be categorized in two main groups: The objects of the 1st group (11 objects) are made of copper–silver alloys in which copper content varies within 30–60 wt% while silver content varies within 25–40 wt%. The objects of the 2nd group (7 objects) are made of nearly pure copper with copper content varying within 85–97 wt%. Though all the investigated metallic objects are found in the Bronze Age layers of the Kalate Shoori site, amazingly, no traces of tin were observed in their elemental composition. The measured impurities in the investigated objects could be either due to the raw materials and minerals used in the extraction of copper and silver or due to the soil surrounding the buried objects. Examination of trace elements contents in the investigated objects reveal that objects with the base of copper–silver alloys (i.e., objects of the 1st group) were all fabricated from the same raw materials, while objects with the base of nearly pure copper (i.e., objects of the 2nd group) were fabricated from different mineral materials with either no arsenic content or with varying arsenic contents of more than 1.5 wt%. Comparison of the results of this work with the published data in the literature indicates that similar samples with the base of copper–silver alloys belonging to Bronze Age have already been found in Altin Tepe, Turkmenistan. It could then be concluded that similar techniques might have been employed in the two regions. Moreover, archeological findings at the Kalate Shoori site reveal that there should be cultural and commercial exchanges between this region and the Central Asia.

Sampling and combined Pb and Ag isotopic analysis of ancient silver coins and ores

The combination of Pb and Ag isotopes in silver coins, artefacts, and ores greatly helps identifying ancient metal sources and detecting alteration such as lead addition, ore mixing, and metal recycling. The present study proposes a new set of procedures suitable for high-precision analysis of lead and silver isotopes in Ag-bearing ores and ancient silver coins. The protocols for combined Pb and Ag extraction and purification are based on multi-step ion-exchange and reversed-phase partition chromatography. In addition to conventional drilling, which irreversibly damages the silver object being sampled, a new method was developed to collect metal from silver coins by etching their edges with a solution of hydrogen peroxide and ammonia (H2O2 + NH4OH), either pure or with added dispersed silicon carbide (SiC) to increase etching efficiency, a technique that only damages the coin patina. This technique can also be applied to silver artefacts other than coins with minor modifications to adapt to different object shapes. Multi-collection inductively-coupled plasma mass spectrometry (MC-ICP-MS) was used to measure the isotopic compositions of both Pb and Ag in ores and coins. Variations in Pb and Ag isotopic compositions are uncorrelated for all the material analyzed, whether ores or silver coins, which demonstrate that isotope variability results from physically different processes. Evidence of mixing between different components is observed for ores, while etched and drilled coins show a conspicuous range of Pb and Ag isotopic compositions. The latter is interpreted as resulting from mass-dependent fractionation during surficial alteration under oxidizing burial conditions, and from patina formation. Silver in patina is isotopically light due to the formation of Ag2S, while the layer below the patina is isotopically heavy. Preliminary patina removal followed by H2O2 + NH4OH etching with suspended SiC may be used as an alternative to coin drilling when the latter is not possible such as for rare and precious coins. The present techniques will further help distinguish primary Pb isotopic variability in artefacts and coins from secondary variations due to underground interaction with the water table, weathering from prolonged burial, and curatorial handling.

Gold-Catalyzed Conversion of Highly Strained Compounds.

The past decade has witnessed the golden age of homogeneous gold-catalyzed reactions, especially those that involve the transformation of highly strained molecules into complex molecular architectures. Gold catalysts, with unique electronic properties and catalytic abilities, have elevated versatile reaction modes through π-interaction induced activation. On the basis of increasing research interest in this topic, together with the significant development of various ligands, including phosphine ligands and azacyclic or noncyclic carbene ligands, the understanding of the catalytic function of gold catalysts has become much deeper and more comprehensive. Different reaction needs thus could be adapted by a novel gold catalyst with a diversified ligand selection. Furthermore, the whole evolution of the gold catalysis on synthetic methodologies has realized and expanded its application into natural product synthesis as well as the potentiality of drug discovery, which endows this ancient metal with a magnificent renaissance. The reactivity of strained small ring molecules with high tension has always been an important research topic in organic chemistry. When the highly strained small ring is linked with a π-electron rich moiety or contains a heteroatom, the gold activation of the π-system or coordination with the heteroatom can initiate a cascade reaction, usually followed by ring opening or expansion. These processes can result in the rapid construction of complex and distinct molecular structures, many of which feature in biologically important molecules. In this review, we will mainly summarize the advances on diverse reaction types and molecular constructions accomplished by homogeneous gold catalysis using highly strained substrates, including methylenecyclopropanes (MCPs), vinylidenecyclopropanes (VDCPs), cyclopropenes as well as aziridine- and epoxide-containing molecules, focusing on the last 10 years. For functionalized alkynyl cyclopropanes, several early inspiring and elegant examples will be described in this review for systematically understanding these transformations.

Geochemical changes during Egyptian copper smelting? An experimental approach to the Ayn Soukhna process and broader implications for archaeometallurgy

This paper presents the results of comprehensive geochemical analysis of experimental copper smelting products. An iterative, long-term experimental programme has been incorporated in the ongoing excavation of Middle Kingdom metallurgy remains at Ayn Soukhna (Egypt) in order to better understand the copper production chain at the site. The integration of archaeometry into this research methodology has enabled a detailed understanding of the geochemical changes which may occur during copper smelting in furnaces of this type. These include significant elemental fractionation, as well as important shifts in lead isotope ratios between ores and end products (slag and copper). This research presents an interpretative framework not only for understanding production waste from Ayn Soukhna itself, but more broadly the provenance and technology of copper alloys circulating in ancient Egypt. The significant shifts in lead isotope ratios observed for an experimental low-lead copper smelting system are highly relevant here, given the similar composition of many Sinai and Eastern Desert ores exploited throughout Pharaonic history. However, the implications of this research may be extrapolated beyond Egypt to low-lead copper provenance research across the ancient world and thus provide an important new methodological perspective for archaeometallurgy more generally. Furthermore, limitations to using iron in copper artefacts as a guide for their production technology are pointed out. Similar iron contents are observed for wood- and charcoal-based smelting systems, inviting a reappraisal of fuel use at ancient metal production contexts in Egypt and elsewhere. A research approach integrating excavation, experimentation and analysis is essential when confronting the complexity of production chains underlying Egyptian copper artefacts. While daunting, this generates more nuanced interpretative frameworks for studying copper provenance and technology.