Late Antique Glass Research Articles

Late Antique Glass Carving as Cross-Craft

Focusing on the related engraving techniques of openwork and opus sectile carving as evidence, this paper demonstrates that glass production in the Eastern Mediterranean in late Antiquity was an example of cross-craft, involving aspects of specialised collaboration among glass producers. As such, it represents the interdependence required of inter-industry relations in terms not only of resources but fundamentally of skills. Beyond just glass, cold-worked carving in various media suggests relatively large-scale late Roman urban production was more likely defined by a transferrable skill set (in this case carving) as opposed to a material.

Beads of Alexandria: Non‐invasive analysis of glass from Roman, Late Antique and Islamic Kom el‐Dikka, Egypt

AbstractWritten sources indicate that Alexandria in Egypt was a leading producer of Roman glass. Furthermore, archaeological finds have provided evidence for the local production of drawn glass and gold‐in‐glass beads, which were distributed throughout the world. In this study, we present an analysis of the chemical composition of more than two hundred glass objects from the Roman (2nd–3rd/4th century ce) and Late Antique (4th/5th–7th century ce) glass bead workshops located at Kom el‐Dikka in Alexandria. This study is based on the results of portable X‐ray fluorescence (pXRF) analyses carried out on raw glass, bead semi‐products, products and waste from both periods. Additionally, the glass chemistry of some Islamic (8th–12th century ce) beads found at the site has been analysed.Despite the limitations of the method, the vast majority of samples exhibited compositions confirming their general dating and Egyptian origin. Remarkably, a single bead was made of high‐alumina glass and appeared to be an import from India, possibly a remnant of the Indo‐Pacific glass bead route that connected Red Sea ports and Europe in Late Antiquity. In addition, we offer a new analytical approach to the method that has potential to enhance the value of pXRF in the analysis of archaeological glass.

Unravelling the role of iron and manganese oxides in colouring Late Antique glass by micro-XANES and micro-XRF spectroscopies

This research aims to understand colouring technologies in 5th–7th centuries glass imported to Atlantic Britain by correlating the iron (Fe) and manganese (Mn) ratios and oxidation states with colour. Despite having a similar matrix chemical composition and concentrations of Fe and Mn oxides, these vessels display different colours (from green to yellow/amber, sometimes with purple streaks). Colour changes can be induced by controlling the reduction-oxidation reactions that occur during glass production, which are influenced by the raw materials, furnace and melt atmosphere, and recycling. To evaluate these parameters, reference glasses were prepared, following the composition of Late Antique archaeological glass recovered from Tintagel (UK) and Whithorn (UK). A corpus of archaeological and experimental glass samples was analysed using bulk Fe and Mn K-edge x-ray absorption near edge structure (XANES) spectroscopy, micro-XANES and micro x-ray fluorescence (μ-XRF) at beamline ID21, at the European Synchrotron Radiation Facility. Fe and Mn XANES spectra of the archaeological glass indicate that Fe and Mn are in a similar oxidation state in all the yellow samples, predominantly Fe3+ and Mn2+. No detectable difference in Mn and Fe oxidation state occurs in the purple streaks compared to the yellow glass bulk but μ-XRF maps of the distribution of Fe and Mn show that Mn is more concentrated in the purple streaks. This indicates that the purple colour of the streaks is mainly due to a higher Mn/Fe ratio and persistence of more oxidised manganese in the purple areas, even though it is difficult to detect. Many archaeological fragments appear pale green in transmitted light but amber in reflected light. XANES studies detected the presence of surface layers where manganese is more oxidised. This layer is believed to scatter transmitted and reflected light differently and might be responsible for the optical features of the archaeological glass.

Late Antique glass vessels in life context of population of eastern black sea littoral – Colchis (NW Georgia): performance, function and trendy

This article presents typological repertoire of late antique-early byzantine glass vessels from archeological sites of NW Georgia (mainly of historical Apsilia). They show how regional industries responded to the needs of their community in the Black Sea littoral. However, this way I made visible an ideological interaction of regional markets of Pontic areas. While the vessel forms, decoration and impact of new technologies made possible to discuss why they are eventually distinguishable from other parts of the Black Sea region. But my approach to these vessels has been influenced generally by funding context and by different communities of glass owners. Because the glass vessels become a regular part of daily life of special warriors of area and the most spectacular ones entered the wealth of military aristocracy. This gives a fairly accurate picture of their transportation purpose in Colchis. In addition, there is at least five rarest vessels with own specimen which leads to local production. Some attests considerable attention by concept originated in Mesopotamia and leads the new phenomenon attracted people in early Christianity. Out of limited vessels associated different periods, some even owned over the centuries. All this are indication that we still know very little about their specific purposes.

The contribution of archeometry in characterization of decorative materials from the site of Villa di Teodorico in Galeata (Italy)

Villa di Teodorico in Galeata (Forlì-Cesena, Emilia Romagna) is an important archeological site in the north of Italy occupied from sixth century BC to twelfth century AD. The most interesting results concern the Roman age, when a large villa was built, and the late antiquity, when the Ostrogothic king Theodoric decided to build in this area his palatium (early sixth century AD). The archeometric investigation was performed on Roman wall paintings fragments and on late antique glass sectilia fragments belonging to Palazzo di Teodorico by using a multi-technique approach that included micro-Raman spectroscopy, scanning electron microscopy with energy-dispersive spectroscopy, X-ray powder diffraction, UV–visible–NIR diffuse reflectance spectrophotometry with optic fibers and optical stereo-microscopy.. This analytical approach allowed the identification of all components, collecting molecular, elemental, microscopic, morphological and chromatic data. The characterization of samples supplied essential archeological, historical and technological information. The production techniques and the rich materials employed suggest the importance of the site in different periods. The evolution of the manufacturing technologies and the possible trade routes mainly during late antique period are witnessed by the change in the raw materials.Graphical abstract

The glass finds from the Vetricella site (9th-12th c.)Introduction

We examine here the glass finds from the Vetricella site. This site, investigated during the ERC-Avanced nEU-Med project (www.neu-med.unisi.it ) is interpreted as the centre of the royal curtis of Valli attested in documentary sources from 937. During the excavation, a large number of glass objects dated from the 4th to the 12th centuries were unearthed. The compositions of the early mediaeval Vetricella glass vessels (beakers, goblets, bottles, ampoules/vials), are studied and compared with those of similar finds from various other European sites. With the exception of one glass bottle, made with Syro-palestinian plant ash soda glass, all the other studied glasses belong to Antique or Late-Antique natron glass groups (Mn- and Sb-decolorized, Foy 2 and HIMT). All these objects illustrate the recycling practices of Antique and Late Antique glass in Europe as they are described by Theophilus for the 11th and 12th centuries.

Roman and Late Antique Glass in the Mediterranean Area and Serbia: Its Production, Compositional Types and Provenance

Roman and Late Antique Glass in the Mediterranean Area and Serbia: Its Production, Compositional Types and Provenance

An archaeometric perspective on selected Roman and Late Antique glass finds from Dobrudja

This paper reports the results of Prompt Gamma Activation Analysis (PGAA) analyses on 21 glass fragments discovered at Tropaeum Traiani, Carsium, Ulmetum, and Altinum, Constanţa County, Romania, dated to the 1st-6th c. AD. The chemical data indicate a broad palette of compositions: Sb-colorless, Mn-colorless, Sb-Mn colorless, typical blue-green Roman, Série 2.1 and Série 3.2 of Foy glass. A plant ash glass sample was identified – most likely a fragment of a vessel imported from the Sasanian Empire.

Chemical analyses on late antique glass finds from Histria, Romania

AbstractThis paper reports the chemical composition of 36 glass finds from Histria, Romania, mainly dated to the Late Antique period (4th–6th c. AD) obtained by Prompt Gamma Activation Analysis (PGAA) at the Budapest Neutron Centre (BNC). Histria glass fragments were identified as Série 2.1, Série 3.2, and Série 3.3 of Foy, HIMT, Roman, and Sb decolorized. Most of the analyzed objects were manufactured from glass originating in Egyptian primary workshops. These analytical results are an additional proof for the trade connection of Histria with the rest of the Roman Empire.

Chemical analyses on Roman and Late Antique glass finds from the Lower Danube: the case of Tropaeum Traiani

Chemical analyses on Roman and Late Antique glass finds from the Lower Danube: the case of Tropaeum Traiani

Manganese-Containing Inclusions in Late-Antique Glass Mosaic Tesserae: A New Technological Marker?

The present study focuses on manganese-containing inclusions identified in late-Antique glass tesserae, light brown/amber and purple in colour, from Padova (Italy), in order to clarify the nature of these inclusions, never identified in glass mosaics until now, and provide new insights on the production technologies of such kinds of tesserae. Multi-methodological investigations on manganese-containing inclusions were carried out in this work by means of optical microscopy (OM), scanning electron microscopy (SEM), micro-X-ray diffraction (micro-XRD), electron backscattered diffraction (EBSD), electron microprobe (EMPA), and micro-Raman spectroscopy. The combination of analytical results shows that inclusions are crystalline, new-formed phases, mainly composed of manganese, silica and calcium, and are mineralogically ascribed as a member of the braunite-neltnerite series, with unit-cell parameters closer to those of neltnerite. However, the low Ca content makes such crystalline compounds more similar to braunite, in more detail, they could be described as Ca-rich braunite. The occurrence of such crystalline phase allows us to constrain melting temperatures between 1000 and 1150 °C, and to hypothesize pyrolusite, MnO2, as the source of manganese. In addition, it is worth underlining that the same phase is identified in tesserae characterised by different colours (light brown/amber vs purple due to different manganese/iron ratios), glassy matrices (soda-lime-lead vs soda-lime) and opacifiers (cassiterite vs no opacifier). This suggests that its occurrence is not influenced by the “chemical environment”, revealing these manganese-containing inclusions as a new potential technological marker.

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 sensuFoy 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.

The elusive early medieval glass

In graves 322 and 310 of the early medieval Nin – Ždrijac cemetery three glass vessels, two stemmed goblets and one bottle were found. They have been interpreted as remains of Late Antique glass production, but a closer look brings further information. The best comparisons for the goblets come from the North Adriatic area while the bottle is most probably of early Islamic production. Interesting possibilities of interpretation arise with the graves being furnished with glass products of such different origin at a time when local secondary glass production seems to have been absent.

Study on the colouration of Bulgarian late-antique and medieval archaeological glass finds by a validated total reflection x-ray fluorescence procedure

Study on the colouration of Bulgarian late-antique and medieval archaeological glass finds by a validated total reflection x-ray fluorescence procedure

Unravelling provenance and recycling of late antique glass from Cyprus with trace elements

Earlier research has shown that several common late antique glass types circulate in Cyprus between the fifth and the seventh century AD, specifically Levantine 1, HLIMT, HIMTa, HIMTb and Egypt 1, HIT, Roman and a plant ash glass. By investigating the glass material from Yeroskipou-Agioi Pente, Maroni-Petrera, and Kalavasos-Kopetra, we aimed to refine the chemical groups present within three late antique Cypriot sites and define the relations between trace elements obtained from LA-ICP-MS. Our data demonstrate compositional patterns that can be exploited to provenance late antique glass by investigating the REE-bearing mineral fractions, the amount of zircon and the carbonaceous fraction of the sand. In addition, Nb and Ti display a strong linear relation which depends on the glass type. Finally, the paper discusses the occurrence of glass recycling on the island and how this activity influenced the concentration levels of specific trace elements. Our study thus sets out an analytical framework to identify recycling events tailored on each compositional type.

New geochemical and isotopic insights into the Late Antique Apulian glass and the HIMT1 and HIMT2 glass productions—the glass vessels from San Giusto (Foggia, Italy) and the diagrams for provenance studies

The research focused on a collection of 37 Late Antique glass fragments, found at the archaeological site of San Giusto (southern Italy). The analyses performed by SEM-EDS, EMPA and LA-ICP-MS showed that all samples are constituted by natron-based soda-lime silica glass and allowed clarifying the distinction between Egyptian HIMT1 and HIMT2 productions. The comparison with the composition of the available glass reference groups was verified through three ternary diagrams (provided here for the first time). The results grouped San Giusto samples into HIMT1 (7 samples), HIMT2 (8 samples) and Levantine (13, plus maybe other 3 samples) productions. A convincing provenance assignment was not feasible for six samples only. The isotopic analyses (87Sr/86Sr and 143Nd/144Nd), performed on a selected set of ten samples, provided further information both in terms of glass technology and provenance, as well as in terms of reference groups characterisation. Particularly, the results demonstrated that nine out of a total of ten samples were made using a limestone-bearing sand enriched with variable amount of marine shells and provided further evidence for the distinction of the HIMT1 and HIMT2 groups; the latter overlapping the Levantine field in the 87Sr/86Sr versus eNd binary diagram. From a technological point of view, the importance of separating the likely ‘fresh’ materials from those intentionally recycled or coloured was put into clear evidence, especially in relation to provenance assignments. Lastly, an interesting technological feature has been observed in sample no. 9, where the composition of the main body of the vessel turned out to be different from that of the handle. This result provided clear evidence of the fact that different glass batches could have been used for the different parts of a single vessel body.

Chemical and Oxygen Isotopic Composition of Roman and Late Antique Glass from Northern Greece

The present paper emphasizes the importance of measuring the oxygen isotopic and chemical compositions of ancient glass, in order to constrain some features such as age, raw materials, and production technologies and to identify the “fingerprint” of local productions. In this context, thirty-nine Roman and late Antique glass samples and eight chert samples from northern Greece were selected and analysed for their oxygen isotopic and chemical compositions. Results show that the majority of glass samples are produced using natron as flux and have δ18O values of about 15.5‰, plus or minus a few tenths of one per mil, suggesting that raw materials probably come from Levantine area. Four samples are heavily enriched in 18O, and their chemical composition clearly shows that they were made with soda plant ash as flux. Isotopic and chemical data of Greek chert samples support the hypothesis of local production of the above samples. About half of the glass samples have chemical compositions, which allow their age to be constrained to the late Antique period. For the remaining glass, similarities with literature compositional groups are reported and discussed.

The transition from Roman to Late Antique glass: new insights from the Domus of Tito Macro in Aquileia (Italy)

The present paper focuses on the archaeological, chemical and isotopic characterisation of glass finds from the Domus of Tito Macro (former Domus dei Fondi Cossar) in Aquileia (Italy), dated between the 1st and the 7th century AD. The assemblage comprises both vessels and glassworking residues, including a few chunks. Aims of the study are the identification of the main glass compositions and their contextualisation in Roman and Late Antique reference groups, and of provenance of primary glass. Chemical analyses were conducted by XRF and EPMA. All the analysed fragments are silica-soda-lime glasses, produced with natron as a flux, and are compositionally similar to the Roman coloured (intentionally and unintentionally) and colourless (antimony-, manganese-, and antimony + manganese-decoloured) groups and to the Late Antique groups HIMT, Série 3.2 and Levantine 1. Specific compositional traits of HIMT glass circulating in the north-Adriatic area and a scarcity of Levantine 1 glass are evidenced. The presence of rare HIT blue glasses including a chunk suggests that colouring took place also at primary stage of production. Sr and Nd isotopic analyses, performed on a selection of samples, confirmed the eastern Mediterranean origin of the glasses, although with minor internal differences depending on the compositional group. Chemical and isotopic data suggest a continuity between the Roman and Late Antique glassmaking in terms of sand deposits and sand/flux ratio, although with a major change in the decolouring technique after the 4th century AD. The prompt reception of the Late Antique glass compositions took place in Aquileia alongside the persistence of earlier compositions, probably with the aim of satisfying different segments of the glass market.

Glass groups, glass supply and recycling in late Roman Carthage

Carthage played an important role in maritime exchange networks during the Roman and late antique periods. One hundred ten glass fragments dating to the third to sixth centuries CE from a secondary deposit at the Yasmina Necropolis in Carthage have been analysed by electron microprobe analysis (EPMA) to characterise the supply of glass to the city. Detailed bivariate and multivariate data analysis identified different primary glass groups and revealed evidence of extensive recycling. Roman mixed antimony and manganese glasses with MnO contents in excess of 250 ppm were clearly the product of recycling, while iron, potassium and phosphorus oxides were frequent contaminants. Primary glass sources were discriminated using TiO2 as a proxy for heavy minerals (ilmenite/spinel), Al2O3 for feldspar and SiO2 for quartz in the glassmaking sands. It was thus possible to draw conclusions about the chronological and geographical attributions of the primary glass types. Throughout much of the period covered in this study, glassworkers in Carthage utilised glass from both Egyptian and Levantine sources. Based on their geochemical characteristics, we conclude that Roman antimony and Roman manganese glasses originated from Egypt and the Levant, respectively, and were more or less simultaneously worked at Carthage in the fourth century as attested by their mixed recycling (Roman Sb-Mn). In the later fourth and early fifth centuries, glasses from Egypt (HIMT) and the Levant (two Levantine I groups) continued to be imported to Carthage, although the Egyptian HIMT is less well represented at Yasmina than in many other late antique glass assemblages. In contrast, in the later fifth and sixth centuries, glass seems to have been almost exclusively sourced from Egypt in the form of a manganese-decolourised glass originally described and characterised by Foy and colleagues (2003). Hence, the Yasmina assemblage testifies to significant fluctuations in the supply of glass to Carthage that require further attention.

Late Antique Glass Vessels and Production Indicators from the Town of Herdonia (Foggia, Italy): New Data on Cao‐Rich/Weak HIMT Glass

AbstractIn the framework of the archaeometric research on Apulian Late Antique glass, a collection of 24 glass vessels (third to seventh centuries ad) and production indicators found at Herdonia (Foggia, Italy) was examined, by means of SEM–EDS, EMPA, ICP–MS and LA–ICP–MS. A fragment of crucible was further investigated by SEM–EDS and EMPA. The results obtained were discussed together with another glass collection from Herdonia previously investigated. The full set of 48 samples was made of siliceous sands mixed with plant ashes (two samples: a dark green slab and a colourless beaker/lamp) or natron (all the other 46 samples). The latter were assigned to the following compositional groups: HIMT, Levantine 1, RNCBGY1, RNCBGY2, RC/LAC‐Sb, intermediate HIMT/RNCBGY1, intermediate RNCBGY1/HIMT, intermediate Levantine/RNCBGY2 and two other groups, the CaO‐rich HIMT and the CaO‐rich/Na2O poor HIMT, which showed a prevailing Adriatic distribution and a close similarity to the weak HIMT glass group. Most Herdonia samples were similar to the HIMT productions, and thus of likely Egyptian origin, while a smaller number of samples referred to the Levantine productions.