La fouille archéologique du quartier Velotte à Montbéliard : nouvelles données sur des opérations de chimie oubliées

La publication de fouilles archéologiques anciennes menées en 1993 et 1994 à Montbéliard, rue Velotte au bourg Saint-Martin, avaient négligé des objets se rapportant à la distillation et à la métallurgie. L'étude physico-chimique présentée ici d'une petite coupelle, ou récipient réfractaire destiné à affiner les métaux précieux, associée à une enquête dans les archives permet de mettre en évidence un atelier d'essai de minerais de cuivre argentifère vers 1600

Some problems and potentials of the study of cupellation remains: the case of post-medieval Montbéliard, France

Bone-ash cupels are increasingly identified in medieval and later archaeological contexts related to the refining of noble metals in alchemy, assaying, jewellery or coin minting. These small finds may provide information on metal refining activities, the technical knowledge of different craftspeople, and the versatility of laboratory practices, which often differed from the standard protocols recorded in metallurgical treatises. This paper is centred around a late 16th-early 17th century cupel excavated in Montbéliard, France. The analytical study by optical microscopy, ED-XRF and SEM-EDS allows the cupel to be ascribed to the assaying of the silver content of an ore sample, which is supported by local historical and geological information. The manufacture of the cupel, made of a mixture of wood ash and bone ash, is also addressed, as well as the limited technical efficiency of the operation. This leads to a wider discussion of different recipes for the manufacture of cupels, documented historically and archaeologically, and involving the combination of various raw materials such as bone, wood ashes and clay. This variability raises interesting questions about the existence of diverse technical traditions, and the material properties and performance of different cupels in their specific contexts. In order to facilitate comparisons, we propose that the study of cupellation remains is most informative when it combines microscopy and microanalysis. The role of experimental approaches to these questions is also discussed.Les coupelles en cendres d'os sont de plus en plus nombreuses à être reconnues dans des fouilles médiévales ou modernes. Elles sont utilisées pour l'affinage de métal précieux par les alchimistes, les essayeurs, les orfèvres ou encore les monnayeurs. Ces artefacts peuvent fournir des informations sur les techniques d'affinage, les savoir-faire et les pratiques de l'atelier qui souvent sont différentes des recettes et procédés décrits dans les textes métallurgiques. Cette étude concerne une coupelle de la fin du xviesiècle ou du début du xviie siècles découverte en fouille à Montbéliard (France). Les analyses, par microscopie optique, MEB-EDS, et ED-XRF permettent d'associer la coupelle à l'essai d'un échantillon de minerai de cuivre argentifère, hypothèse confirmée par l'étude des sources écrites et géologiques locales. La fabrication de la coupelle, faite d'un mélange de cendre de végétaux et de cendre d'os est également abordée comme les limites et l'efficacité de l'opération. Ces résultats mènent à une discussion plus large sur les différentes recettes de fabrication de coupelle grâce aux sources écrites et archéologiques qui indiquent des matières premières diversifiées comme la cendre d'os, la cendre de végétaux et la terre. Cette variabilité soulève des questions intéressantes sur l'existence de traditions techniques diverses ainsi que sur les propriétés et l'efficacité de ces coupelles. À des fins comparatives, nous concluons que l'étude de ces artefacts est plus efficace en associant la microscopie et la microanalyse. Enfin, le rôle des approches expérimentales à ces questions est également discuté

Of forming, gilding and intentionality in Pre-Columbian goldwork: analytical characterisation of artefacts from the Museo del Oro, Bogotá

The analytical study of ancient metalwork is a useful strategy to characterise past technologies, but in contrast with other American metalworking traditions this approach has been relatively limited in the context of pre-Columbian Colombia. As a contribution to this emerging research area, this paper presents the results of a compositional and technological study on seven gold alloy artefacts from the collections of Museo del Oro, Bogotá D.C., Colombia, focusing on alloy selection, forming technologies and surface treatments. The artefacts come from four different metalworking regions, and include personal adornments, a votive figure, and an unidentified sheet fragment. Surface imaging and microanalyses were carried out by scanning electron microscopy with energy dispersive spectrometry (SEM-EDS). X-ray mapping was undertaken to gain further insight into depth and nature of surface treatments and internal microstructures. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) data was also collected, enabling cross-analytical technique comparisons and the collection of trace element data. The results allow the identification of alloying technologies and forming methods, as well as the characterisation of corrosion products and gilding layers, and discussion of the intentionality of the latter where present. The case studies are discussed in relation to the existing pool of evidence and used to assess the potential for further analyses on the region’s metalwork.Institute of Archaeometallurgical Studies, MSc Scholarship Arts and Humanities Research Council, PhD Studentship, AH/L503897/1 British Academy, SG-5424

The Provenance, Use and Circulation of Metals in the European Bronze Age: The state of debate

Bronze is the defining metal of the European Bronze Age and has been at the center of archaeological and science-based research for well over a century. Archaeometallurgical studies have largely focused on determining the geological origin of the constituent metals, copper and tin, and their movement from producer to consumer sites. More recently, the effects of recycling, both temporal and spatial, on the composition of the circulating metal stock have received much attention. Also, discussions of the value and perception of bronze, both as individual objects and as hoarded material, continue to be the focus of scholarly debate. Here, we bring together the sometimes diverging views of several research groups on these topics in an attempt to find common ground and set out the major directions of the debate, for the benefit of future research. The paper discusses in turn issues of: geological provenance of new metal entering the system and how to determine and interpret it; the circulation of extant metal across time and space, and how this is seen in changing compositional signatures; and some economic aspects of metal production. These include the role of metal-producing communities within larger economic settings, quantifying the amount of metal present at any one time within a society, and aspects of hoarding, a distinctive European phenomenon that is less prevalent in the Middle Eastern and Asian Bronze Age societies.Funded by the McDonald Institute for Archaeological Researc

Chymistry and crucibles in the Renaissance laboratory : an archaeometric and historical study

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

The casts of Pompeii: Post-depositional methodological insights

The casts of Pompeii bear witness to the people who died during the Vesuvius 79 AD erup tion. However, studies on the cause of death of these victims have not been conclusive. A previous important step is the understanding of the post-depositional processes and the impact of the plaster in bones, two issues that have not been previously evaluated. Here we report on the anthropological and the first chemical data obtained from the study of six casts from Porta Nola area and one from Terme Suburbane. A non-invasive chemical analysis by portable X-ray fluorescence was employed for the first time on these casts of Pompeii to determine the elemental composition of the bones and the plaster. Elemental profiles were determined providing important data that cross-referenced with anthropological and strati graphic results, are clearly helpful in the reconstruction of the perimortem and post-mortem events concerning the history of these individuals. The comparative analyses carried out on the bone casts and other collections from burned bones of the necropolis of Porta Nola in Pompeii and Rome Sepolcreto Ostiense, and buried bones from Valencia (Spain), reveal the extent of high temperature alteration and post-depositional plaster contamination. These factors make bioarchaeological analyses difficult but still allow us to support asphyxia as the likely cause of deathBEAGAL18/00110, Dr Gianni Gallello, Conselleria de Innovacio´n, Universidades, Ciencia y Sociedad Digital, Generalitat Valenciana, PROMETEO 2019-056, Dr M. Luisa Cervera, Horizon 2020 Framework Programme, H2020- MSCA-IF-2015-704709-MATRIX., Dr Gianni Gallell