Roman glass is studied here by means of optical absorption spectroscopy, in order to provide an objective method to quantitatively evaluate colour. The dataset is composed of 165 soda-lime silicate ...glass samples from various western European sites, mainly dated from the first to fourth century AD, and containing variable amounts of iron, manganese and/or antimony. Iron redox ratios and colour coordinates (based on the CIELab colour system) are determined and put in relation with the thickness of samples and their manganese/antimony contents. Results reveal thickness as a crucial parameter when discussing glass hues, thus leading to a differentiation between the ‘intrinsic’ and ‘perceived’ colour of glass objects (i.e. the colour of the object with the thickness normalised to 1 mm, and that with its original thickness, respectively). Apart from HIMT and purple glass, the concentration of ferrous iron appears to be correlated with
a
* — a colourimetric parameter determining how green the glass is. Significant relations of antimony/manganese contents versus iron redox and glass colour are also considered, resulting in quantitative arguments to entitle antimony-decoloured glass as the most oxidised and colourless glass.
Fifty‐seven glass samples from Carthage dating to the fourth to sixth century ad were analysed using the electron microprobe. The results show that these samples are all soda–lime–silica glass. Their ...MgO and K2O values, which are below 1.5%, suggest that they were made from natron, a flux that was widely used during the Roman period. The major and minor elements show that these samples can be divided into four groups, three of which correspond to the late Roman period glass groups that were found throughout the Roman Empire: Levantine I, and ‘weak’ and ‘strong’ HIMT. Of particular interest is our Group 2, which is technologically and compositionally similar to HIMT glass and the CaO and Al2O3 values of which are similar to those of Levantine I. Glass of similar composition has been reported by several authors and is predominantly found dating from the late fifth to seventh century. This could represent a ‘new’ glass group; therefore further study is needed to determine its origin. Also, this study suggests that the Vandal invasion in North Africa did not disrupt the glass trade between Carthage and the Levantine coast.
Research on the cargo of glass in the Roman ship
Iulia Felix, wrecked off the town of Grado (province of Udine, North Italy) in the first half of the 3rd century AD and composed of recycling cullet ...carefully selected for colour and type, provided much information on Roman glass production technology. A combined approach, involving analytical, statistical, and archaeological evidence, included chemical analyses (X-ray fluorescence, electron microprobe), which indicated that the coloured samples were all soda-lime-silica in composition, with natron as flux, although cluster analysis identified many compositional groups. Comparisons among the compositional groups of the colourless glass, previously studied, and those of coloured glass showed that the production technologies of the colourless glass vessels constitute two well-defined technological end-members, also related to group types, into which those of the coloured glass samples fall. In particular, coloured glass samples—all bottles, low-status vessels—were produced with mainly beach siliceous-feldspar-calcareous sand. However, unlike the colourless type, strict control of raw materials and decolourising processes was not adopted, and recycling was also practised, as demonstrated by the Sb
2O
3, Cu and Pb patterns. In this context, a “recycling index” (RI)—(Sb
2O
3)
X/(Sb
2O
3)
Ref
*
100—is proposed here for the first time, in order to quantify the extent of recycling of antimony colourless glass in the batch. RI is valid for glass containing abundant Sb from an end-member of colourless glass. In conclusion, although it cannot be stated unequivocally that the identified compositional trends are related to different production centres or different raw materials, the strong evidence of compositional variability among all the
Iulia Felix glass samples, both colourless and coloured, supports the dispersed production model for Roman glassware and the common practice of recycling in Roman imperial times, especially for low-status vessels.
This paper reports the compositional characterization of eighty-two glass fragments discovered in archaeological contexts at
Tropaeum Traiani
(Adamclisi, Constanţa county, Romania), most of them ...dated to the 4th–6th centuries AD, in an attempt to understand the glass consumption and circulation in the Lower Danube region during the Late Antique period. The analytical results were obtained using external Particle Induced X-ray Emission (PIXE) and Particle Induced Gamma-ray Emission (PIGE) techniques at the New AGLAE accelerator located in the basement of the Louvre Palace, Paris, France. The chemical data were compared to those on coeval glass finds from the literature. The naturally colored
Tropaeum Traiani
glass fragments turned out to belong to
Série 2.1
of Foy,
Série 3.2
of Foy, HIMT (high iron manganese titanium), and HIT (high iron titanium) compositional groups of Late Antique glass. The lack of color in several fragments was obtained either through the use of antimony or manganese compounds; intermediate recipes for colorless vessels, indicative for recycling procedures, were evidenced as well. The sample set also included several naturally colored blue and green glasses dated to the Early Roman period which showed compositional patterns typical for Roman Imperial glass. The variety in the chemistry of the vitreous finds reported in this paper, demonstrated by the identification of different glass types previously encountered in contemporary objects from many archaeological sites from the Mediterranean Sea and Balkan Mountains regions during the Late Antique period, reflects the trade connections of the settlements from the Lower Danube and the Black Sea region with the rest of the Roman world.
X-ray fluorescence analytical techniques were applied to two pieces of glass fragments because they are believed to be sampled from two pieces of important glassware, a facet-cut bowl and a ...deeply-blue colored dish, excavated from Niizawa Senzuka Tumulus No.126, Nara, Japan (late 5th century). Two different provenances were estimated as primary production area for the two glass fragments. One fragment has a chemical composition being a good match with that of Sasanian glass excavated at Veh Ardašīr in central Iraq. Conversely, composition of another fragment is consistent with common blue-green colored Roman glass manufactured during the imperial period. If these glass fragments are actually identical to the ancient glassware excavated from Nara, our results can provide scientific evidence how various cultures were introduced to and accepted by ancient Japan. Concomitantly, they are also evidence of an extremely widespread Silk Road trading from the Mediterranean and West Asia to the Far East of Japan during the 1st millennium AD.
•Two pieces of glassware were excavated from late 5th century tumulus at Nara, Japan.•Nondestructive XRF analyses were applied to tiny glass fragments believed to be sampled from the glassware.•Two different areas, Roman and Sasanian Empires were successfully identified as primary production sites of these two fragments.
Pliny the Elder describes the discovery of a process for making natron glass, which was widely used for much of the first millennium
bc
and
ad
. His account of glassmaking with natron has since been ...corroborated by analyses of archaeological glass and the discovery of large-scale glass production sites where natron glass was made and then exported. Analyses of Egyptian natron have shown it to be a complex mixture of different sodium compounds, and previous experiments to make glass with Egyptian natron have been unsuccessful. Here, natron from el-Barnugi in the Egyptian Nile delta, a site which also probably supplied Roman glassmakers, is used to produce glass. The experiments show that high-quality glass, free of unreacted batch or bubbles, could have been produced from natron in its unprocessed form in a single stage, that larger quantities of natron would be required than has previously been anticipated, that the presence of different sodium-containing compounds in the deposit aided melting, and that negligible waste is produced. The implications for the identification of glass production sites, for the organisation of trade and for the supply of natron within and outside Egypt are discussed in the light of Pliny’s accounts.
During antiquity, it is known that glass was produced in specialized primary workshops in Levant and Egypt, and this glass was melted and formed into objects in secondary workshops, and distributed ...in most cities and towns of the Roman Empire. Great efforts, although it is difficult, have been made to distinguish where it was produced. In this study, we perform chemical analysis on 48 glass samples (22 moils and 26 glass artefacts) dated to the 6th century CE from Vasileos Irakleiou Street, 45, Thessaloniki in northern Greece by using Scanning Electron Microscopy (SEM) with Energy–Dispersive X-ray microanalysis (EDX). All glasses were produced with natron as a flux and based on the sodium oxide content we divided them into two groups. Most of the glasses’ chemical analysis indicates that they originated from Egypt, and can be categorized as HIMT and others as Roman Mn or Roman Mn-Sb. MnO is the main decolorizer, while in some samples MnO coexists with Sb2O3. Finally, recycling processes are evident in most of the samples.
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