The archaeological excavation of the Villa dei Quintili in Rome (2nd century AD) brought to light one of the most impressive residential complexes of the Roman Empire. Among the astonishing number of ...findings, inside and outside the buildings, a large amount of glass mosaic tesserae were gathered from the thermal bath environments. This work reports the results of a microtextural and microchemical characterization of 29 colored opaque glass tesserae, by using an analytical approach that included the use of scanning electron microscopy with energy-dispersive X-ray spectroscopy, laser ablation-inductively coupled plasma-mass spectrometry. The glass is usually a soda-lime-silicate glass, with the exception of red and orange glass tesserae, which showed the typical composition of lead glasses mixed with plant ashes. Red tesserae were likely produced with a natron-based glass mixed with plant ashes, acting as flux and reducing agent. The opacifiers were all antimony-based with different natures according to the chemical composition: calcium antimonates (white in color) and lead antimonates (yellow in color).
In the 29 tesserae studied in this research, the colors of glass were strictly correlated to the concentrations of coloring agents, the two main coloring ions identified were copper, introduced in the majority of samples as bronze scrap, and cobalt. Finally, the levels of trace elements indicate the use of mature sand, rich in quartz and poor in heavy metals and clay minerals, for the production of all samples.
•Vitreous tesserae from Villa dei Quintili have been analyzed.•Chemical composition and production technology of vitreous tesserae have been determined.•SEM-EDS and LA-ICP-MS have been applied on vitreous tesserae analysis.
The results of a programme of compositional analysis on a series of emerald green glass vessels of known form and date suggest that emerald green vessels have distinct characteristics that set them ...apart from most contemporary glasses. These specific compositional peculiarities presented here will be evaluated in the context of the varieties of vessel forms produced in the colour. In the light of our findings we will suggest a number of ways forward in the understanding of the structure of the early Roman glass industry.
•1stC emerald green glass differs compositionally suggesting it was coloured at source.•It is not used for certain common forms raising questions of secondary supply systems.•Some forms have higher Pb, suggesting links to early Pb-Sb colourless glass production.•The alkali is ambiguous; low-K soda ash(es) or ash+natron (linked to colour formation).•The trace element fingerprint is complex, but an Egyptian provenance is proposed.
Aquileia (Italy) is one of the largest Roman cities so far excavated, and is on the UNESCO World Heritage List. The significant amounts of glass found in the site have suggested to many researchers ...that Aquileia played a central role in glass production and trade in ancient times, although only very few archaeometric data have been obtained so far. In this context, an archaeological and archaeometric study was conducted on 62 unintentionally coloured samples of Late Roman glass (late 3rd–6th centuries AD) from the excavation of the Casa delle Bestie Ferite (“House of the Wounded Animals”). Results indicate the importance of Aquileia in the glass trade. Bulk chemistry (EPMA and XRF data) evidences a compositional transition with respect to Early Roman glass (1st–3rd centuries AD), indicating changes in raw materials for glass-making. In particular, the chemical data show the close similarity between Aquileia glass and some of the main compositional groups widespread in the Mediterranean from the 4th century onwards (HIMT, Levantine I, Série 3.2), suggesting their probable common origin in the Eastern Mediterranean. This evidence suggests there was no primary glass production in Aquileia, as presumed in the past by some authors. No relationships between chemical composition, type, chronology or production technique have been observed, although the possible connection between HIMT-type glass and low-quality objects such as bottles cannot be completely excluded and must be better investigated in future research.
•The first systematic archaeometric study on Late Roman glass from Aquileia.•Both archaeological and chemical data are reported and discussed.•The identified compositional groups are similar to coeval ones from Mediterranean.•Low evidence of recycling, suggesting the use of “fresh” glass.•No relationships among composition, type, chronology and production technique.
The process of degradation in artefacts subjected to centuries of burial can be of great relevance above all in archaeological glass. Infrared thermography is a non-destructive method allowing to map ...the defects of the glass substrate, both produced during its manufacturing (e.g., bubbles and inclusions) and due to ageing. This research is focused on the use of different flash thermography methods for the mapping of superficial flakes on Roman glasses dating back to the I and II century A.D. The effectiveness of active thermography methods is evaluated to map degraded portions of archaeological glass considering their semitransparency and specific optical absorption.
Laser ablation inductively coupled plasma mass spectrometry (LA‐ICP‐MS) analyses of loose glass tesserae from the Northwest Quarter of Gerasa/Jerash has enhanced our understanding of the dynamics ...regulating the production and circulation of glass tesserae in second‐ to eighth‐centuries ce Jordan and the diachronic development of mosaics at the site. The identification of Levantine and Egyptian compositions (Roman‐Mn, Levantine I, HIMT, Foy 2.1) proves the continuous production of mosaics from the second to the seventh centuries. The Levantine I tesserae were made by the recycling and colouring of glass cullet. The gilded tesserae, in contrast, were all of an Egyptian base glass, likely illustrating the import of finished tesserae.
The chemical composition of 48 glass finds from Histria and Tomis, Romania, chiefly dated to the 1st-4th c. AD, was determined using prompt gamma activation analysis (PGAA) at the Budapest Neutron ...Centre (BNC). Most fragments have composition typical for the Roman naturally colored blue-green-yellow (RNCBGY) glass; Mn-colorless, Sb-colorless, and Sb-Mn colorless glass finds were evidenced, too. Several Foy
and Foy
glass fragments, as well as an HIMT and a plant ash glass sample, were identified in the studied assemblage. The archaeological evidence, the glass working waste items, and the samples with compositional patterns suggestive of recycling are proofs of the secondary glass working activities at Tomis during the Early Roman Empire period.
Analytical data of Roman and early Islamic glass established several primary glass production groups linked to glassmaking centres in the Levant and in Egypt. In contrast, the activities of secondary ...glass workshops are largely invisible in the compositional fingerprint of first millennium glass. Laser ablation inductively coupled plasma mass spectrometry (LA‐ICP‐MS) of 261 glass finds from the Visigothic settlement of Tolmo de Minateda (Spain) revealed a site‐specific contamination pattern due to secondary glass processing and recycling, namely the enrichment of the glass batch by a unique combination of rare alkali elements (Li, K, Rb, Cs). With a median of 21 ppm, Li is particularly distinctive. Elevated lithium contents (Li>30 ppm) are also one of the characteristic features of Iberian plant ash glass from the Islamic period. The earliest known examples of this type of glass were found among the ninth‐century remains from Tolmo.
Rare alkali element contamination of medieval vitreous materials by both the crucible ceramic and fuel vapour are shown in this work. Systematic recycling of old cullet, using crucibles made from clay from the Central Iberian Massif, resulted in unique trace element patterns that can serve as identifiers of Iberian glass processing.
In the present study, the first archaeometric data on an ample selection of intentionally coloured (or decoloured) Early Roman glass (1st–2nd centuries AD) from the Archaeological Museum of Adria ...(Rovigo, Italy) are reported. The analysed samples are 61 in total, both transparent and opaque, and were characterised from the textural (SEM-EDS), mineralogical (XRPD) and chemical (XRF, EPMA, LA-ICP-MS) points of view. This combined approach allowed us to identify the raw materials and production technologies employed in the manufacture of glassware. Results for the transparent samples show that they are all silica-soda-lime glasses. Most of them, independently of colour, have compositions close to those of typical Roman glass, produced with natron as flux. No relationships were identified among chemical compositions, types or production techniques, but a dependence on bulk composition was identified for some particular colours, revealing the careful and intentional selection of raw materials. This is the case of Sb-colourless glass, produced with sand of high purity, a group of intensely coloured objects, mainly emerald green and black, produced with soda ash as flux, and some blue examples produced with various sources of sand or soda ash as flux. Two main types of opacifiers were identified for the opaque samples: calcium antimonate for white, mauve and blue glasses, and lead antimonate for the yellow ones; in one case, a yellow lead-tin antimonate was also identified. As regards the opaque glasses, most of the samples opacified with calcium antimonate are silica-soda-lime in composition, similar to the typical Roman glass. Instead, samples opacified with lead and/or lead-tin antimonates are lead glasses, suggesting different production technologies.
► An archaeometric study was carried on coloured Early Roman glasses from North-East Italy. ► Raw materials and production technologies of both glass and opacifiers were identified. ► The majority of the samples shows a ‘typical’ Roman glass composition. ► Some particular colours show a dependence on the bulk composition. ► Calcium or lead antimonates are the main opacifiers identified.
PDF
