Iron Smelting Slag Formation at Tell Hammeh (Al-Zarqa), Jordan

3-7 May, 200

Parting layers, ash trays and Ramesside glassmaking: an experimental study

A series of glassmaking and glass colouring replication experiments was undertaken in order to test some of the current hypotheses concerning Late Bronze Age glass production at Qantir-Piramesses. These were based on the model of glassmaking developed in this volume, and aimed in particular to test the behaviour of the parting layer and the local ceramic under the proposed chemical and thermal conditions. Modern ash trays made out of Egyptian Nile silt clay were used as proxies for LBA reaction vessels and crucibles, and both raw glass and coloured glass ingots were produced in them. This experimental study, based on detailed observation and technical studies of archaeological samples from Qantir-Piramesses, not only provides material readily comparable to the archaeological finds, but brings to the forefront practical issues concerning the nature of the parting layer, its application, the melting procedures, the re-use of crucibles, and indirect evidence of primary production, such as the impact of sodium chloride, a major component of plant ashes, on the ceramic. Although this string of experiments does not fully replicate LBA glassmaking technology, much information was obtained and further areas of ambiguity identified

Semi-finished glass from Ile-Ife, Nigeria: Implications for the archaeology of glass in sub-Saharan Africa

The discovery of glass crucible fragments with the remains of semi-finished glass at Ile-Ife, Nigeria, has provided the first evidence for the existence of autonomous glass production in sub-Saharan Africa

Local Quantum Observables in the Anti-deSitter - Conformal QFT Correspondence

Quantum field theory on d+1-dimensional anti-deSitter space-time admits a re-interpretation as a quantum field theory with conformal symmetry on d-dimensional Minkowski space-time. This conjecture originally emerged from string theory considerations. Here, it is proven in a general framework by an explicit identification between the local observables of the two corresponding theories.Comment: Letter based on hep-th/9905179, 4 pages, 1 figur

Changes in glass consumption in Pergamon (Turkey) from Hellenistic to late Byzantine and Islamic times

We present compositional data for nearly 100 glass samples from Pergamon, western Turkey, spanning 1500 years from the Hellenistic to Late Byzantine and Islamic periods. The data shows the use of already-known Roman glass groups during the first half of the time frame, for imported vessels as well as locally worked glass. No compositional change is seen related to the introduction of glass blowing for either of the glass groups in use during this time. During the first half of the 1st millennium AD, two previously little-known boron- and alumina-rich compositional groups emerge. These glass groups, thought to be regionally produced, dominate glass compositions in Pergamon during the mid-to late Byzantine and Islamic periods, indicating a major shift in glass supply and a fragmentation of the economy into more regional units. Plant-ash glass, from the 9th century AD replacing mineral natron glass in the Levant, plays only a minor role in Byzantine and Islamic Pergamon

Ancient glass: from kaleidoscope to crystal ball

Research over the last few decades has greatly enhanced our understanding of the production and distribution of glass across time and space, resulting in an almost kaleidoscopically colourful and complex picture. We now recognise several major ‘families’ of glass composition, including plant-ash based glass in Late Bronze Age Egypt and Mesopotamia, and the Islamic World; mineral natron glass in the Greek, Roman and Byzantine Empires; mineral-based lead- and lead–barium glass in Han period China and medieval Europe; and wood-ash and ash-lime glass in medieval Europe. Other glass groups include a peculiar granite-based glass in medieval Nigeria, and probably mineral-based glass in Bronze Age southern Europe. However, despite two centuries of research, we know very little about the actual production locations and technologies for most of these glass groups, and how and where glass making was invented. The early literature reflects the comparatively limited number of individuals and research groups working on glass; only recently there is a significant broadening of the research community and expansion and refinement of the data base. This enables us now to take stock of our current understanding and identify major lacunae and areas where additional work may make the most significant contributions to our understanding of the complex picture. Hopefully this will help moving from the traditional descriptive and often fragmented opportunistic data-gathering phase (asking ‘what’, ‘where’ and ‘when’) to a more interpretative period looking with fresh eyes at the ‘why’ and ‘how’ of compositional and technical developments. This opening of the research field includes addressing the relationship of the different glass industries to the societies that used glass, and how they organised its production and distribution. A major overarching issue remains the question of the initial invention of glass, and how the idea as well as the material itself spread. Major debates should ask whether there were multiple inventions of glass making; how best to identify and interpret long-distance trade; how to ensure data compatibility and quality; and how to integrate different types of data, from archaeology through craftsmanship and typology to chemistry and optical properties

A (not so) dangerous method: pXRF vs. EPMA-WDS analyses of copper-based artefacts

Analysis of metal objects with portable and handheld X-ray fluorescence spectrometry has become increasingly popular in recent years. Here, methodological concerns that apply to non-destructive, surface examination with XRF instruments of ancient metal artefacts are discussed based on the comparative analyses of a set of copper-based objects by means of portable X-ray fluorescence (pXRF) and electron probe microanalyser (EPMA). The analytical investigation aims to explore issues of instrument comparability and reliability of the non-invasive pXRF results. The different analytical approaches produce a comparable pattern for the major element concentrations, but substantial variation is evident when it comes to the absolute values for major and minor/trace elements

Iron smelting in pre-colonial Zimbabwe: Evidence for diachronic change from Swart village and Baranda, northern Zimbabwe

In conventional reconstructions of southern African archaeology, the production of iron has been seen as unchanging for the last 2000 years. Significantly, this contrasts with the changes that have been noted in broader society and other classes of material culture of the same period. Despite iron being used as a chronostratigraphic indicator, virtually nothing is known on the patterns of iron production within the Iron Age and whether change in technology and the socio-cultural context of production took place. From a combined archaeological and metallurgical perspective, the historical development of iron working has never been explored. For example, it is not known whether similar types of furnaces were constantly operated throughout the last two millennia. Excavations at two sites in northern Zimbabwe, one Gokomere-Ziwa (800 - 1200 cal AD) and one Zimbabwe tradition (1500 - 1700 cal AD), have shown differences in iron pyrometallurgical debris, tentatively suggesting that they represent separate metal working practices. By comparing the archaeological and metallurgical evidence from the two sites, this paper represents an initial step in delineating patterns of indigenous iron production in one region of Zimbabwe

Pločnik: technology of metal production

Metallurgical materials recovered during the excavation campaigns of 2012 and 2013 in Pločnik show similar characteristics to samples already studied and published previously (Radivojević 2012, 2015; Radivojević and Kuzmanović Cvetković 2014; Radivojević and Rehren 2016; Radivojević et al. 2013). They include, as for Belovode (Chapter 11), predominantly malachite minerals and ores (Table 1), that occur as roughly beneficiated pieces and without a distinct spatial patterning in Trench 24. In comparison to Belovode, they occur less frequently across all five horizons, partially explained by the fact that most of Trench 24 is a large rectangular feature – a house (F1=F2=F4=F5=F6=F10), and there is very little economic area surrounding it

The Late Antique glass furnaces in the Hambach Forest were working glass - not making it

The cluster of Late Antique glass furnaces in the Hambach Forest in the Rhineland, western Germany, has been advocated by K.H. Wedepohl and G. Hartmann in their influential papers as a potential location for primary glassmaking. Here, we re-evaluate and expand the original chemical data and assumptions underpinning this controversial interpretation, and present an alternative explanation for the compositional pattern observed among the glass finds from the site and its wider environment. Glass matching very closely the two main chemical compositions as seen in the Rhineland has recently been reported from numerous 4th to 5th century CE sites in Southern France, Britain, Italy, the Balkans and Egypt, with the same pattern of minor amounts of colorant elements such as copper, tin, lead and antimony, as contamination due to the inclusion of recycled cullet into the batch. The high content in iron and related elements, previously seen as a unique characteristic of the Hambach Forest glass finds, is now recognised as a common feature of these established super-regional compositional glass groups. We identify the majority of analysed finds to consist of HIMT glass, followed by a significant number of série 3.2 glass sensu Foy et al. (2003), while only one sample matches glass of the Levantine composition. This sees the furnaces of the Hambach Forest, and the finished vessels excavated in the wider region, fully integrated in the two-tier Late Antique glass industry, where a few eastern Mediterranean mega-producers were supplying their raw glass across the Empire to be re-melted and worked locally into artefacts, including at the cluster of glass furnaces in the Hambach Forest