Raw Glass Research Articles

The glass from the arrabal of Arrixaca (Murcia, 12th-13th centuries)

This article presents an assemblage of 36 glass samples excavated in the urban site of San Esteban, part of the arrabal of Arrixaca (Murcia) (in al-Andalus, an arrabal was a relatively dense urbanised area outside the city walls) in contexts securely dated to the 12th and early 13th century, spanning the rule of Ibn Mardanīš, and the early period of Almohad domination in the city. The samples were analysed by electron microprobe (EMPA) for major and minor elements and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) for trace elements. The results are examined within the context of glass production, circulation, and consumption in al-Andalus and the Islamicate Mediterranean more broadly. The results show that some of the glasses found in San Esteban-Arrixaca may have been imported from other Islamicate regions (Egypt and Mesopotamia), but that the vast majority can be related to previously recognised compositional Iberian glass groups. At the same time, the identification of several fragments of production waste and raw glass suggest that some glass-working facility may have existed in the vicinity of San Esteban-Arrixaca. The compositional evidence also indicates that recycling (including of imported glass objects) may have been a fairly common practice in Andalusi glassmaking, but it is suggested that some of the usual chemical markers of recycling may, in the case of al-Andalus and perhaps also elsewhere in the medieval Mediterranean, be the result of the cross-breeding of glass- and glaze-making activities.

Glass working and recycling in Pompeii: new evidence from the landfill of the Sarno Baths (VIII 2, 17–23)

Forty-six glass finds, including vessel fragments, windows, one inlay and one indicator of production (moil) excavated in the dump of the Sarno Baths in Pompeii were selected for an interdisciplinary technological, typological and chemical study. The identification of the moil demonstrates that a glassblowing workshop most likely existed in Pompeii, thus putting an end to a long-standing scientific debate. The LA-ICP-MS chemical data show that Roman-Mn base glass predominates, along with few Egyptian natron-type glasses and some plant-ash glass of probable Egyptian origin as well. A large proportion of the analysed glass, including the moil, consists of recycled compositions, suggesting the existence of an efficient system of collection and recycling of glass, which was active even at a time when the city had an abundant supply of fresh glass. The demand for raw glass in Pompeii far exceeded the average demand of other Roman towns, because glass containers were essential for the flourishing perfume industry in Pompeii and Campania. The proximity of the Sarno dump to the perfume district in the south-western part of the city and to the horrea of the Sanctuary of Venus suggests the possible location of the glass workshop in this area.

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.

Back to black: Analysis of the earliest natron glass found in Italy

An assemblage of black-appearing glass objects (predominantly beads) that is dated to the 9th–7th centuries BCE and found in Iron Age contexts of Southern Etruria and Latium (central Italy) was analysed using portable X-ray fluorescence spectrometry, laser ablation – inductively coupled plasma – mass spectrometry and micro-Raman spectroscopy. The analytical approach allowed us to discuss the technology of glass-making in a period of relevant technological changes. It resulted that the glass that reached the Italian peninsula was somewhat different, from a compositional point of view, from both earlier and later periods. The data collected showed that iron – the main colouring agent for these glasses – was obtained from several sources as was silica – the main component of glass. Lime, one of the main constituents of many types of glass, plays a modest role in this assemblage, which places these samples in a special position because of the peculiar batch formula. At least three centres of raw glass production are suggested by the compositional data, but in each case the glass was imported to the Italian peninsula.

Facile purification of glass fiber powder by sedimentation for enhanced epoxy resin composites

Glass fiber powder contains two distinct forms: crumb-shaped and rod-shaped glass fiber powder particles. The shape and size of the particles in glass fiber powder have a great influence on its application. In order to separate rod-shaped glass fiber, the effects of different dispersants, such as SHMP, NaOL, and Na2SiO3 on them were investigated by settling experiments. Zeta potential, X-ray photoelectron spectroscopy (XPS), optical microscope, and other methods were used to analyze the adsorption behavior and settling mechanism. Three-point bending experiment and dynamic mechanical analysis (DMA) were used to evaluate the performance of epoxy resin composites reinforced with the raw glass fiber powder and the rod-shaped glass fiber powder. The results show that SHMP can effectively separate crumb-shaped glass fiber powder and rod-shaped glass fiber powder, leading to a notable increase in sedimentation recovery difference, up to Δ=51.08%. A preferential sedimentation separation mechanism is proposed to elucidate the settling mechanism. When the content of glass fiber powder and rod-shaped glass fiber is 5%, the glass transition temperature shifts significantly towards higher values, leading to the optimum comprehensive mechanical properties of the composites. Compared with the original epoxy resin, the flexural strength increased by 10.38% to 95.18 MPa and by 20.11% to 103.57 MPa. Similarly, the storage modulus increased by 14.14% to 2083 MPa and by 21.64% to 2220 MPa.

HfTiO4 transparent thick film phosphors activated with Eu3+, Dy3+, and Tb3+ ions

Hafnium (Hf)-based double oxides show promise as high-efficiency scintillators due to large effective atomic numbers and high relative density. However, the preparation of these scintillation crystals is challenging due to their high melting points and incongruent melting behavior. In the present study, we demonstrated that the chemical vapor deposition (CVD) of single-phase HfTiO4 films on quartz glass substrate was successfully deposited at temperatures ranging from 973 to 988 K, with a TiO2 molar ratio in the precursor vapor of 25–45 mol% TiO2. The deposition rate of HfTiO4 reached 36 µm h−1. The films exhibited an in-line transmittance of 78 % relative to the raw glass substrate at a wavelength of 600 nm. When activated with Eu3+, Dy3+, and Tb3+ ions, the HfTiO4 films displayed red, yellow, and green photoluminescence emissions originated from the 4f–4f transitions of each trivalent rare-earth ion under ultraviolet light irradiation. HfTiO4 exhibited no intrinsic background emission, suggesting that the addition of a selected activator could yield a phosphor with the desired emission color range.

Early age structural build-up and pore stability in raw foam at ambient conditions: Implications for the final properties of glass-ceramic foam

Alkali activation followed by foaming techniques is an effective method for glass-ceramic foam development where early-age reactions in the alkali-activated precursors and the foaming reaction happen simultaneously. Therefore, this early reaction stage must be clearly understood to control the pore characteristic in the glass-ceramic foams. However, correlations between early-age structural build-up and foaming stability and their consequences on the final properties of the sintered glass-ceramic foams have not been investigated. This research aims to examine this relationship. 80–95 wt % of waste glass and 5–20 wt % of slag were used as alkali-activated precursors in this research. Using the alkali activation and combined foaming technique, the raw glass foam was developed and hardened at ambient conditions. The early-age reactivity and structural build-up of the binder and foamed suspension were studied through the rheological parameter and chemical structure analysis over the hardening period. During the hardening process, the percolation effect and development of reaction gels contribute to network formation and stability of the foamed suspension. As the hardening time increases, the matrix strengthens, and the pores stabilise through crosslinking of the gels. After hardening, the raw glass foams were sintered and their properties were evaluated and correlated with early-age structural build-up in fresh glass foam. This study demonstrates that the early-age interaction during matrix development and the foaming process controls the pore stability, connected pore volume, and strength of the final glass-ceramic foams. By understanding these parameters, the properties and pore stability in final glass-ceramic foams can be controlled effectively.

Composition and affinities of glass from the Ma'agan Mikhael B shipwreck, Israel

AbstractMaterial recovered from the Ma'agan Mikhael B shipwreck, off the coast of northern Israel, includes a significant assemblage of glass, which appears to represent waste workshop material (cullet) collected for recycling. Twenty‐three samples were selected for analysis for major and minor elements using SEM‐EDS, to provide insight into the activities and dating of the ship. The glass corresponds to known primary glass types, comprising a high‐ and a low‐lime subgroup of Levantine 1 (Apollonia type), and Egypt 1b. The assemblage is likely to date to the early part of the eighth century CE and, in conjunction with the radiocarbon dating of the ship, gives a possible date range for the wreck of 710–740 C.E. All groups contain glass‐working waste, glass chunks, and vessel fragments, and the majority are likely to have been collected from one or more workshops. It is unclear whether this cargo represents the byproducts of several campaigns of a single workshop which used different consignments of raw glass, or material from different workshops, collected at different ports of call.

The Effect of SrO Addition on the Recrystallization of ZrSiO4 in Raw Glass–Ceramic Glazes from the SiO2-Al2O3-CaO-MgO-K2O-ZrO2 System

The aim of this experiment was to determine the effect of the addition of strontium oxide on the recrystallization of zirconium silicate when adding strontium oxide to the glaze composition. Zirconia glazes (four different contents) were prepared, to which strontium oxide was added in amounts of 0, 1, 3, 6, and 12 mass% SrO. The characteristic temperatures of the raw glazes were measured, based on which the maximum firing temperatures were determined. The fired glazes were subjected to a study of their phase compositions and an observation of their microstructures. An analysis of the characteristic temperatures showed a fluxing effect, but it was not as strong for all glazes. Differences in the amount of the crystalline phase of zirconium silicate obtained in the fired glazes, as well as the partial transition of zirconium silicate to the amorphous phase, were observed. Observations of the microstructure clearly indicated an increase in the homogeneity of the distribution of zirconium silicate.

The Non-Invasive Characterization of Iron Age Glass Finds from the “Gaetano Chierici” Collection in Reggio Emilia (Italy)

This work reports the results of the analyses performed on a set of glass finds from the “Gaetano Chierici” collection in the Civic Museums of Reggio Emilia. Forty-eight typologically heterogeneous glass finds were included in the list of the analyzed objects, dating from the fifth century BCE to the first century CE. The objects primarily consisted of glass beads; however, bangles, pinheads, and one vessel fragment were also included in the set. The items were analyzed using non-invasive spectroscopic methods that were implemented with portable equipment on the museum’s premises. Fiber optic reflectance spectroscopy was used to identify the coloring species in the glass matrix, while X-ray fluorescence spectrometry provided compositional information. Both techniques allowed for a discussion of the mechanisms of coloring and opacification, as well as the raw materials used for this purpose. The results provided a complex picture of the various colorants used to manipulate the appearance of the glass, which was a crucial aspect in the creation of the personal adornments represented by these glass items. The data revealed evidence of different sources of raw glass and colorants. Most of the samples were colored with cobalt, but iron and copper also influenced the color of many of them. Both white and yellow were utilized for the glass decorations, and these colors were achieved with the addition of either antimony-containing crystals or tin-containing ones. This finding suggests that the transition from antimonate to stannate started as early as the second century BCE. The “Gaetano Chierici” collection contains representative objects distributed throughout the investigated period. The results obtained here are a starting point for future studies of glass technology and provenance in the area.

Raw glass and glassworking practices beyond the Roman limes: A case study of the late Roman workshop in Komarov (Middle Dniester, Western Ukraine)

AbstractThe chemical composition of 42 samples of raw glass from the Komarov settlement on the Middle Dniester was studied by means of SEM-EDS, EPMA and LA-ICP-MS analyses. We singled out groups of colourless glass of Levantine and Egyptian origin, the chronology of which indicates that the workshop could be dated to the 4th – early 5th century. The data on the chemical composition of the raw glass do not confirm that glassmaking industry existed here in an earlier period, as was previously believed. The manufacturing in Komarov combines the use of high-quality perfectly decolourized raw glass with intensive use of cullet, which might point out either different levels of the glassware manufactured here, or selective recycling. The characteristic features of the workshop's raw glass supply are the absence of the HIMT glass and late spread of antimony-decolourized glass.

An archaeometric contribution to the interpretation of blue-green glass beads from Iron age Central Italy

Several types of (mostly) blue-green glass beads from Iron-Age archaeological sites in Central Italy were studied using a range of spectroscopic techniques: portable X-Ray Fluorescence spectrometry, Fibre Optics Reflectance Spectroscopy, Scanning Electron Microscopy coupled with Energy Dispersive X-ray Spectrometry, micro-Raman spectroscopy and Laser Ablation Inductively Coupled Plasma Mass Spectrometry. Complementary information was gathered from each technique and discussed in the frame of the archaeological typology of the objects. The systematic evaluation of the results allowed us to draw some conclusions on the raw materials employed for primary production and to highlight some provenance indicators in the glass. Some of the beads found in the Iron Age (IA) contexts were preliminarily attributed to the Final Bronze Age (FBA) production based on their typology, and the compositional data obtained in this work confirmed that they were low magnesium high potassium (LMHK) glass, typical of FBA in the Italian peninsula. Other beads were assigned to low magnesium glass (LMG) or high magnesium glass (HMG), thus giving further information on the fluxing agents employed in the Early Iron Age (EIA) and beyond. Colour variations among the beads reflected their chemical composition, with different bead typologies coloured in a specific way. In some instances, it was possible to establish different origins for the colouring raw materials. The provenance of the samples was difficult to place, but the chemical evidence suggested a subdivision within the raw glass used to produce the beads: for one set of samples, a local origin of the glass could be hypothesised, whereas several production sites in the Near East were suggested for most of the beads considered in this study. Some preliminary clues for the local working of imported glass were also highlighted for one typological group.

Metal prills in primary glass: A puzzling aspect of the production process

Primary glassmaking in the first millennium CE during Roman and post Roman periods was conducted in large heating installations, the so-called tank furnaces, in two main regions of the East Mediterranean, namely the Levant and Egypt. Especially in Israel, a large number of tank furnaces in various sites such as Apollonia, Bet Eli’ezer (Hadera) and Jalame have been discovered, giving new insights regarding the technology of glassmaking in the first millennium CE.In this paper, we investigate the existence of metal prills embedded in raw glass at the contact layer with a tank furnace floor. The glass chunks were found in a refuse pit at Umm ez-Zinat, southern Carmel, Israel, and are dated to the Late Roman-Early Byzantine periods (fourth-early fifth centuries CE) based on glass vessels found with the debris of primary and secondary production. Another three prills from Bet Eli’ezer, the massive glass industry dated to the seventh-early-eighth centuries CE, were also analysed to compare any similarities/differences between the prills from the two sites.Results show that the prills vary greatly in shape and composition. Their morphology ranges from rounded spheres to asymmetric ellipses, all showing inclusions indicating the source material was chemically heterogeneous. The prills from Umm ez-Zinat are mainly lead, with minor contribution of copper, tin, antimony and silver as inclusions. Two of the three prills from Bet Eli’ezer are copper alloyed with lead, and one has a lead matrix with various copper inclusions. We investigate possible scenarios to understand the nature of the metal in the glass, how and when it was added to the glass melt, and possible technological and ritual interpretations for its presence.

Microstructural control of MgO–Al<sub>2</sub>O<sub>3</sub>–SiO<sub>2</sub> glass-ceramics using titanium oxides with varying particle sizes and crystallinities as nucleation agents

Microstructural control of MgO–Al2O3–SiO2 (MAS) glass-ceramic (GC) with precipitated enstatite (MgSiO3) in the 0.68–12 µm range from a parent glass having one composition was achieved by using titanium oxides with varying particle sizes and crystallinities as nucleation agents. Specifically, compared with the MAS-GC prepared using TiO2 with 50–200 nm and relative high crystallinity (TiO2-L-H), the MAS-GC prepared by mixing TiO2-L-H with TiO2 having single nanometer size and relative low crystallinity displayed an increase in the average crystal particle size from 6.0 to 12 µm with the preservation of volume fraction. In addition, compared with the MAS-GC prepared using TiO2-L-H, the MAS-GC prepared by TiO2 having single nanometer size and relative high crystallinity exhibited a decrease in the average size of crystal particle from 6.0 to 0. 68 µm with a decrease in the volume fraction from 76 to 67 %. Therefore, these results indicated that the particle size and crystallinity of the raw glass materials are key parameters for controlling the microstructure of GCs.

Late antique and early medieval glass from the northern Venetian lagoon: New data from the archaeological site of Jesolo

Accurate microchemical characterisation was performed on a 4th-12th-century repertoire of coloured and colourless glass samples found in the archaeological excavation of Jesolo (ancient Equilus, northern Italy).The research aimed to improve the state-of-the-art knowledge of early medieval glass, through the characterisation of a stratigraphically very well-dated and homogeneous glass collection, further representing a unicum in the area of the western upper Adriatic.A representative sampleset of sixty-seven glass finds -including vessels, windows, tesserae and blocks of raw glass- was investigated by electron microprobe (EMPA) and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). All samples are classified as soda-lime-silica glass made of impure sands and natron. In most cases, glass colour is imparted by iron naturally present in the sands, often counteracted by varying levels of manganese. The collection also includes numerous Co– and Cu-coloured glass. Colourless glass is Mn-decoloured or, to a lesser extent, Mn/Sb-decoloured. The proportion between fresh and recycled glass is almost equal. The provenance investigation has established that while Levantine imports are numerically limited, most materials can be traced back to the Egyptian area. Among the twelve samples assigned to the Levantine area, both Jalame-type and Apollonia-type glass has been identified in an almost equal percentage. Among Egyptian glass, a consistent group of 22 samples has been straightforwardly assigned to the HIMTa and, to a lesser extent, HIMTb groups. Both group 2.1 and 3.2 are clearly attested in almost equal amounts but individually less frequent than HIMT.

An Improved Hyperplane Assisted Multiobjective Optimization for Distributed Hybrid Flow Shop Scheduling Problem in Glass Manufacturing Systems

To solve the distributed hybrid flow shop scheduling problem (DHFS) in raw glass manufacturing systems, we investigated an improved hyperplane assisted evolutionary algorithm (IhpaEA). Two objectives are simultaneously considered, namely, the maximum completion time and the total energy consumptions. Firstly, each solution is encoded by a three-dimensional vector, i.e., factory assignment, scheduling, and machine assignment. Subsequently, an efficient initialization strategy embeds two heuristics are developed, which can increase the diversity of the population. Then, to improve the global search abilities, a Pareto-based crossover operator is designed to take more advantage of non-dominated solutions. Furthermore, a local search heuristic based on three parts encoding is embedded to enhance the searching performance. To enhance the local search abilities, the cooperation of the search operator is designed to obtain better non-dominated solutions. Finally, the experimental results demonstrate that the proposed algorithm is more efficient than the other three state-of-the-art algorithms. The results show that the Pareto optimal solution set obtained by the improved algorithm is superior to that of the traditional multiobjective algorithm in terms of diversity and convergence of the solution.

The glass in early al-Andalus

The expansion of Islam in the western Mediterranean led to far-reaching changes in the conquered societies. The study of glass assemblages found in archaeological contexts dating back to the early centuries of al-Andalus, coupled with analytical research and written sources, has emerged as a valuable resource for analysing these transformations. In eighth and early ninth centuries glassmakers were forced to recycle late antique materials due to the end of raw glass imports from the East but also, they developed new glassmaking methods using locally available resources. The import of eastern finished vessels served as prototypes of the new shapes and decorations to the vessels produced in the workshops of al-Andalus. These changes resulted in the long term in the configuration of clearly “Islamised” wares, in a different system of glass production and distribution from that which prevailed from antiquity to the Visigothic period.

Reconstruction of the Holocene Paleogeography of Bani Salama, Wadi El‑Natrun, Egypt

Wadi El-Natrun depression lies about 100 km north-west of Cairo, just south of the ‘desert road’ between Cairo and Alexandria. The depression has a longitudinal morphology extending from the southeast to the northwest with average dimensions of about 60 km × 15 km. Bani Salama site lies in the eastern part of the depression, to the east of Fasda Lake, which is located at -27 m below sea level. Based on a geomorphological survey and local archaeology, we found that the site has been occupied by human societies since at least around 4000 years before the present. The site contains ruins of a temple and a castle dating back to the 12th Dynasty of the Pharaonic period (1985-1773 BC). The site also contains workshops of raw glass production dating back to Egypt’s Roman period (31 BC – AD 395). The aim of this study is to investigate the Holocene marsh deposits of Bani Salama, which are located between the Pliocene plateau and Fasda Lake. A sediment core (NAT-11) was taken from the site in June 2015. This core is investigated to understand the Holocene palaeo-geography, palaeoclimates and human impacts.

Стекло могильника Фронтовое 3 в Юго-Западном Крыму: хронология, динамика распространения и производственные центры (по данным химического состава)

The chemical composition of vessel glass from the cemetery of Frontovoe 3 has been studied with SEM-EDS technique. This cemetery, located on the outskirts of Sevastopol (south-western Crimea) and dated from the late first to the early fifth century AD, was completely investigated during the excavation campaign of 2018. The dataset containing 144 samples of colourless, naturally coloured, and purple glass allows for a conclusion that all the glass found at Frontovoe 3 comes from the Egyptian and Levantine glassmaking centres, and the Egyptian glass predominates at all stages of the cemetery. Nevertheless, the chronology of the groups of glass, singled out according to the chemical composition, sometimes differs from their time of distribution in the European provinces of the Roman Empire and the Mediterranean area. In this study the groups have been dated according to the archaeological context (i. e. considering the chronology of the burials with the glass vessels). In the early part of the cemetery four groups have been singled out: Roman blue-green (group 1, late first and second (mostly its first half) centuries); Roman colourless (group 2, second to the mid-third centuries); glass decoloured with antimony (group 3, second and third centuries); “mixed” Sb-Mn glass (group 4, second and third centuries). The colourless glass close to the Levantine I group by composition (group 5, from the mid-third (or slightly earlier) to the mid-fourth century) concentrated in the “transition” zone of the cemetery. The changes in the raw glass supply to the south-western Crimea took place in the fourth, similarly to what happened in the European provinces of the Roman Empire. In the late area of Frontovoe 3, there are glass finds showing the composition close to the series Foy-3.2, Foy 2.1, and HIMT group (groups 6-8), with very few pieces of the HIMT glass. These groups become widespread in the fourth century (possibly, excluding its early period) and existed to the abandonment of the site. The group 9, likely of the “mixed” composition due to the extensive glass recycling, dates from the same period. The selection of forms made of glass of group 4 and their serial occurrence in the burials of Frontovoe 3 implies the extensive use of recycled Mn-Sb glass in the local production (in Chersonese?) from the period synchronous to the early stage of the cemetery. Later on, raw glass of the Levantine (group 5) and Egyptian (groups 6, 7) origin was possibly supplied to Chersonese for the local glass working. In the latest period of the cemetery, the proportion of recycled glass was possibly high, although it is less evident due to the limitations of the SEM-EDS technique.

:Metal Finds and Coins: Final Publications from the Danish-German Jerash Northwest Quarter Project II

:<i>Metal Finds and Coins: Final Publications from the Danish-German Jerash Northwest Quarter Project II</i>