Shape as a measure of weapon standardisation: From metric to geometric morphometric analysis of the Iron Age ‘Havor’ lance from Southern Scandinavia

© 2018 Traditionally, standardisation of manufacture has been investigated using metrics (e.g. length and width) and compared in terms of the coefficient of variation (CV). This paper argues that standardisation should not only be investigated via metrics, but also in terms of shape. An Iron Age lance head type (‘2018;Havor‘2019;), known from three main weapon depositions in Southern Scandinavia, is used as a case study to test the effectiveness of shape analysis against traditional metric analysis for investigating standardisation. Geometric morphometric (GMM) analysis is used to measure the overall shape variation and to test shape difference of the same lance type coming from three different archaeological sites. The results demonstrate GMM to complement the traditional metric approach. Whilst metric measurements offer insights into Havor lance standardisation, the results from multivariate analysis of GMM data provides further explanation about the source of variation in terms of shape, including an assessment of object symmetry. This paper represents the first known methodological application of GMM analysis to iron weapons and demonstrates it to be an effective method for studying product standardisation in terms of shape variation

Technology, Use and Reuse of Gold during the Middle Period: The Case of Casa Parroquial, Atacama Desert, Chile

The life-histories of gold artefacts can provide rich insight into technology and culture, but so far the potential of this research approach has not been exploited in the south central Andes. Here we present the analysis of 34 gold and silver objects from the Middle Period cemetery of Casa Parroquial (San Pedro de Atacama, northern Chile), using pXRF, SEM-EDS, PIXE and digital microscopy. Chemical analyses detected variable compositions (2.4–73.1 per cent Ag and 0.2–3.4 per cent Cu) suggesting that artisans used both native gold and artificial gold-silver-copper alloys. Based on their manufacturing techniques, quality and designs, we identify two working styles, one technically more ‘careful’ than the other. Given their elemental and technological variety, together with the lack of local production evidence, we propose that these artefacts were imported as finished objects from Tiwanaku or Cochabamba and northwest Argentina. However, we identify a series of objects that were modified or reshaped as they entered a new cultural context, revealing complex life-histories. Modifications used relatively simple mechanical means: punching, cutting and folding, most likely made in multi-craft contexts by non-metallurgists from San Pedro.Chilean Government and CONICYT (Becas Chile Postdoctorado); ANID projects 3200229, 11130651 and 1160849; UCL Institute of Archaeology; The Coghlan Bequest funding of the Historical Metallurgy Society; 7th Framework Programme of the EU (CHARISMA Grant Agreement n. 228330

The prehistoric individual, connoisseurship and archaeological science: The Muisca goldwork of Colombia

Unlike art historians, archaeologists rarely make systematic attempts at attributing artefacts to individual artisans - they stop at the broader category of 'provenance regions' or 'technical styles'. The identification of archaeological individuals, however, allows detailed insight into the organisation of workshops, knowledge transmission, skill, and the tension between individual and social agency. This paper reviews the potential of archaeological science methods to identify individual artisans through the study of material culture. Focusing on the Muisca votive goldwork of Colombia, it combines stylistic, chemical and microscopic analyses to identify idiosyncratic motor habits, material selections and artistic preferences that allow the identification of individual makers and manufacturing events. The results are informative of the internal dynamics between the Muisca technological tradition, religious behaviour and craft specialists. We conclude by outlining the potentials and challenges of science-based archaeological connoisseurship in other contexts

Of gold masks, bronze mirrors and brass bracelets: Analyses of metallic artefacts from Samdzong, Upper Mustang, Nepal 450–650 CE

© 2019 Elsevier Ltd The site of Samdzong is composed of a series of shaft tombs situated at 4000 m altitude in the Himalayas. Recent archaeological expeditions have recovered an exceptional metal assemblage including gold and silver masks, copper vessels, iron daggers, brass bangles and a bronze medallion. The richness and variety of the collection provided an unusual starting point to investigate trade and regional exchange patterns in the period 450–650 CE, in combination with data from other materials. Here we present a stylistic, metallographic, elemental and isotopic study of a selection of the metal objects. The results suggest a South Asian origin for the bulk of the metals, while evidencing a variety of technological and cultural traditions that show connections with Central Asia and the Silk Road. This is one of the first comprehensive analyses of archaeological metal objects from the High Himalayas, offering a baseline for future comparative studies

Effects of alloy composition in traditional Japanese shakudo patination

Japanese craftspeople have dominated the art of patinating copper-alloys since the 15th century, using precise alloy compositions and complicated patination processes in different hot solutions to create a variety of colours on swords fittings such as tsuba. While this complex tradition is increasingly popular in the East, the reasons behind the choices made by craftspeople in the selection of the components of the alloys and are still not fully understood. This paper investigates the effect of different alloying elements (tin, gold, and silver) on the resulting patina. Experimental results are compared with optical and compositional analyses on historical Japanese artefacts, confirming the effects of the different alloying elements on the patina characteristics and colour. The absence of tin and the presence of gold limit the growth of an oxide layer and promote the formation of a thin patina characterised by a smooth appearance without visible grains. Therefore, a limited thickness of the patinas is a key aspect for the production of the desired colour and appearance of the patinas. The first colorimetric analysis on historical Japanese artefacts demonstrates the influence of gold, silver and tin in the final patina colour, validating the observations in the experimental replicas

Heat transfer properties of post-medieval crucibles

In the present case study, the thermal conductivity of two post-medieval crucibles was determined. The investigated crucible fragments represented two broadly contemporary production sites, Großalmerode and Obernzell, which were employing different types of raw materials (sand tempered kaolinitic clays and natural graphitic clays, respectively) and different firing conditions. The samples were part of a larger assemblage, which had been studied in view of production technology and function of pyrotechnical ceramics in post-medieval Europe and in view of dissemination of products from different production centers. The study results were expected to provide complementary information regarding the technology and use of the crucible

Bullion production in imperial China and its significance for sulphide ore smelting world-wide

Gold and silver production was of major importance for almost all ancient societies but has been rarely studied archaeologically. Here we present a reconstruction of a previously undocumented technology used to recover gold, silver and lead at the site of Baojia in Jiangxi province, China dated between the 7th and 13th centuries AD. Smelting a mixture of sulphidic and gossan ores in a relatively low temperature furnace under mildly reducing conditions, the process involved the use of metallic iron to reduce lead sulphide to lead metal, which acted as the collector of the precious metals. An experimental reconstruction provides essential information, demonstrating both the significant influence of sulphur on the silicate slag system, and that iron reduction smelting of lead can be carried out at a relatively low temperature. These new findings are relevant for further studies of lead and precious metal smelting slags world-wide. The technological choices of ancient smelters at this site are then discussed in their specific geographical and social-economic settings

Iridium to provenance ancient silver

© 2017 Elsevier Ltd Trace levels of iridium in ancient silver artefacts can provide information on the sources of silver-bearing ores as well as the technologies used to extract silver. A geographically and chronologically disparate legacy dataset, comprised of Near Eastern objects from the Sasanian and Byzantine Empires (1st Millennium AD) and coins circulating around the Mediterranean in the mid-1st Millennium BC, shows that Ag-Au-Ir log-ratio plots can help identify silver derived from the same mining areas, as well as broadly differentiating between the ore types exploited. Combining trace element and lead isotope analyses through the Pb crustal age of the ore, further delimits interpretations on the compositions and locations of silver ore sources. Furthermore, it is shown that silver artefacts of Near Eastern origin have exceptionally high iridium levels, suggesting a unique silver-bearing ore source, potentially in the Taurus mountain range of southern Anatolia. The wide range of crustal ages identified for ancient Greek coins and Near Eastern objects suggest that the addition of exogenous lead as a silver collector during smelting was common practice in the Near East as early as 475BCE. The practice of mixing silver from different sources has also been identified by triangulating the log-ratio subcomposition plots, Pb crustal ages of the ore from which the silver derived and absolute values of trace levels of gold and iridium in silver artefacts