Raw Glass Research Articles

Compositional identification of 6th c. AD glass from the Lower Danube

A group of finds (vessels, raw glass chunks, window panes) from three sites in present-day Bulgaria was selected as representative of the circulation and usage of glass in the Lower Danube region during the 6th c. AD. In total, 79 samples were analysed by EPMA and/or LA-ICP-MS techniques. The data quality was assessed for each analytical run according to the measurement of reference glasses and to pairs of results obtained from representative samples of archaeological glass analysed by both techniques. Combining EPMA and LA-ICP-MS data allowed a sufficiently consistent and unified set of primary results to be formed. As already suggested in an earlier preliminary paper, only a single glass composition was found to dominate the 6th c. contexts in the region. The current study recognises this 6th c. glass from the Lower Danube as identical with the so called ‘Serie 2.1.’ defined by D. Foy and co-workers (2003) in various assemblages in Southern France and North Africa. The major, minor and trace oxide evidence presented here indicates that this is a distinct primary glass composition, with an iron-rich sub-group tentatively differentiated within the main group. Accordingly, an attempt is made to situate it relative to the other main primary compositions in the region. The proposed interpretation is that the 6th c. glass should not be linked to the HIMT glass despite the nominal similarity between them due to their elevated iron oxide, manganese, and titania concentrations. Instead, a possible link between the geochemical characteristics of the 6th c. glass and an earlier group of manganese decolourised glass, equivalent to ‘Serie 3.2.’ outlined by D. Foy and co-workers (2003) is suggested. This may imply the use of sand from a broadly identical geological area, hence it is possible that both the 6th c. glass and the manganese decolourised composition are likely to share a common origin.

Injection-Molded Soft Magnets Prepared from Fe-Based Metallic Glass: Mechanical and Magnetic Properties

The injection-molded metallic glass soft magnet is prepared from the powder of melt-spun ribbon of Fe36Co36B20Si4Nb4 glassy alloy and Nylon 6,6 of wt.% from 5 to 20 via the polymer injection molding technology. The product is characterized by the SEM, mechanical, and magnetic test. The results indicate that this type of materials has comparable mechanical properties and morphological feature with the conventional injection-molded NdFeB magnet and exhibits excellent soft magnetic behaviors. The magnetic properties of the injected magnets are compared with the raw metallic glass, solvent-casted resin bonding magnets, and thermal-treated magnets to confirm that the processing temperature of Nylon injection does not affect the magnetism. The injection technology is a practical processing method to be applied on the metallic glass for potential usage.

Archaeological and archaeometric study of the glass finds from the ancient harbour of Classe (Ravenna- Italy): new evidence

The present study focuses on Late-Roman/Early Medieval glass found in the productive area within the ancient harbour of Classe near Ravenna, one of the most important trade centres between the 5th and 8th centuries AD of the Northern Adriatic area. Aims of the study were the identification of the main glass compositions and their contextualisation in Late-Antique groups; the identification of provenance of raw glass, and, consequently, of commercial routes; the extent, if any, of recycling glass cullet, as an alternative to the import of fresh raw glass; the identification of possible connections between archaeological typology and glass chemical composition. 32 glassworking wastes and 25 drinking vessel fragments for a total amount of 57 fragments were devoted to chemical analysis in XRF and EPMA. All the analysed fragments are silica-soda lime glasses, produced with natron as a flux, and are compositionally similar to Late-Antique groups HIMT, Serie 3.2 and Levantine1. Raw glass chunks, glassworking wastes and objects of comparable compositions are identified into HIMT and Serie 3.2 groups, while the Levantine 1 group includes only objects and glassworking wastes. Systematic comparisons between Classe and Aquileia, the two most important Late-Antique archaeological sites of North-Eastern Italy, were also carried out, and the same compositional groups were identified, although Serie 3.2 in the Classe assemblage is more represented. Sr and Nd isotopic analysis confirmed that the composition of the three glasses derive from coastal sands of the Syro-Palestinian and Egyptian shore, with a slight shift in comparison to the published data. Little evidence of recycling was identified in the assemblage. In the 5th century, a secondary glass workshop devoted to the shaping of glass vessels starting from raw glass chunks and, possibly, glass cullet, was active in the area of the harbour. Raw glass of HIMT and Serie 3.2 was imported from the Levant and Egypt. Comparisons between Classe and Aquileia show that during the Late Antiquity these sites seem to be supplied of raw glass by the same trade routes. In addition, some connections between types and chemical compositions were highlighted.

Experimental and numerical analysis of crack-free DPSS laser dicing of borosilicate glass

We demonstrate the possibility of the crack-free laser dicing of borosilicate glass. The effect of a polymer layer is analyzed on the laser (diode-pumped solid-state, 355 nm, nanosecond) dicing capability of a commercial glass (Borofloat®33) for backend packaging. The main drawbacks concerned the brittleness of glass and photothermal ablation which induces thermal stresses responsible for chipping or cracks. It was assumed that a thick enough polymer would enhance the energy coupling between the beam and the target. The effect of pulse energy and speed on the scribing depth is provided in the present article. A numerical simulation using COMSOL® Multiphysics was performed in order to analyze the volume temperature distribution. It revealed that the temperature remained higher than the working point of glass (1,500 K) between two pulses. The viscosity is thus low between two pulses, and thermal stresses are diminished compared to the processing of raw glass samples.

Herding cats – Roman to Late Antique glass groups from Bubastis, northern Egypt

Eighty-seven glass fragments from Roman and Late Antique layers at Tell Basta/Bubastis in the Eastern Nile Delta were typologically evaluated and chemically analysed to determine chronological and compositional patterns of glass use at this important Egyptian city, and how this relates to larger pattern of glass production and consumption in the first half of the first millennium AD. Bubastis is situated in geographical proximity to Alexandria, an important seaport, and at the same time close to the raw glass production areas in the Wadi Natrun and Sinai peninsula. This paper reports the first substantial set of compositional data of Roman to Late Antique glass from a settlement in northern Egypt, filling an important gap in our knowledge of glass consumption pattern in the first half of the first millennium AD. The glass from Bubastis falls into several compositional groups known already from elsewhere in the Roman and Late Antique world, including antimony- and manganese-decoloured glass and two varieties of HIMT glass. Changes in glass composition over more than 500 years are in line with earlier observations concerning changes in prevalence of these glass groups. However, compositional groups known to dominate archaeological glass assemblages elsewhere, such as Roman blue/green during the earlier part of the period under study, or Levantine I in the later period, are notably absent. For the later period, this is probably due to the proximity of Tell Basta to the suspected production region of HIMT glass in northern Sinai/Egypt. By analogy, this might indicate that the earlier Roman blue/green glass has a production origin further away from the Delta than the decolourised glasses prevailing in Bubastis. A particular vessel type, small-volume thick-walled dark green unguentaria, is made of probably Egyptian plant ash glass, indicating the existence of a specialised glassmaker during the early first millennium AD.

Composition data of a large collection of black-appearing Roman glass

Jewels and tableware made of black-appearing glass were popular in the Roman Empire. Compositional changes (due to modifications in glassmaking technology and use of raw materials) over the period considered (1st-5th century AD) have been investigated on a large number of samples originating from various archaeological excavations in Europe, Northern Africa and the Near East. In the course of this work, over 400 samples of Roman glass, the greatest part of them deeply coloured glass fragments, were embedded into acrylic resin and mechanically ground and polished in order to obtain flat surfaces of unaltered glass. The samples were analysed with scanning electron microscopy/energy dispersive X-ray spectroscopy and the quantification was performed by using a standard-less ZAF software. The trace elements contained in a selection of glass samples were determined via laser ablation-inductively coupled plasmamass spectrometry. The data collected in this study show that from about 150 AD a change in the black glass production process occurred, involving coloration of raw glass made with iron in the secondary workshops. Furthermore, from the 4th century AD on we can observe a change in the type of raw glass used, while the colouring process was maintained. The main aim of this paper is to provide glass scholars with the analysis results, as reference and comparison for further studies.

Analysis of Early Medieval Glass From Excavations at ‘Piazza Bovio’, Naples (Italy)

The archaeological excavation of ‘Piazza Bovio’ at Naples has yielded a large deposit, characterized by exceptional findings relating to the production of a glass workshop dated to the sixth to seventh centuries ad. The workshop features, coupled with the presence of broken glass for recycling and abundant glass scrap, leads us to identify the area as part of a secondary workshop. Selected finished objects and glass scraps were characterized by SEM/EDS and LA–ICP–MS and compared with major compositional groups of glass recognized in the western Mediterranean during the first millennium ad. The aim is to verify the hypothesis of a secondary production in Naples, using raw glass from the Levant area. Three different natron groups were identified on the basis of the colour and the chemical composition. The naturally coloured (blue–green) group is consistent with Levantine I glass. The yellow–green group is associated with HIMT glass, while the colourless glass was produced with different raw materials and probably in another specialized workshop.

The Influence of Different Surface Compressive Stress on the Wettability of Ion-Exchanged Float Aluminosilicate Glass

The effect of the surface compressive stress (CS) on the wettability of the chemically strengthened glasses on air side and tin side was investigated. The wettability of the air side of the raw glass is better than the tin side. After chemical strengthening, the surface energy of the air side decrease with the decreasing of the CS while the tin side is just the opposite. These results demonstrated that the wettability of the chemically strengthened aluminosilicate glass could be controlled by the compressive stress.

Analysis of Roman glass from Albania by PIXE–PIGE method

A series of 31 Roman glasses dated to the 1st–4th c. AD from the present Albania was analyzed by the combined PIXE–PIGE method. The analysis shows typical natron-based glass of the Roman period, though statistical treatment using principal component analysis and bivariate plots reveals four distinct groups, which are qualified by increased levels of potassium, magnesium and titanium–manganese–iron oxides, respectively. MgO content may exceed 2% and reach the level commonly accepted for halophytic plant-ash glass. The groups are formed on account of mineral impurities in the sand, which gives support to the thesis of multiple production centers of raw glass in the imperial age.

Das Gold von Kyros und Johannes: eine Goldschmiedewerkstatt in der Bucht von Abuqir in Ägypten

Underwater excavations of a submerged site in the bay of Abuqir have yielded small finds that indicate workshop activity: short pieces of gold wire, gold splinters, an undrilled bead, copper ingots and coloured raw glass for the production of beads and cameos. In addition, a few pieces of jewellery and accessories were probably made at the site, for instance a glass cameo consisting of the same material as some pieces of raw glass and a finger ring with a bezel in the shape of an oil lamp. For various reasons, the excavated site may have belonged to the pilgrimage shrine of SS Cyrus and John at Menouthis, and oil lamps played an important part at liturgies and healings that were conducted at the shrine. An older account in the 9th-century Coptic miracles of St. Menas refers to a gold workshop of the Holy Apa Apakyri and, therefore, probably to the gold workshop attached to the shrine. The site was active until the early 8th century.

Potential Application of Palm Ash as a Raw Materials in Production of Green Glass

Oil Palm Ash is one of the abundance agricultural wastes found in Malaysia. This wastes need to be disposed properly. Oil palm ash contains compounds needed to produce glass. Most of raw materials (especially silica) used to produce existing commercial glass are imported; therefore it is the best time to highlight the potential of local natural waste as the raw material in glass production. In this study, raw material characterization, glass production and glass product evaluation has been done. A few parameters have been recognized to have effect on green glass production such as mixing compositions and firing temperature. Oil palm ash has been washed and dried then sieved to get uniformity of particle size. Then, oil palm ash is mixed with other glass materials such as alumina and flux and undergone melting process at 1400°C. Through the experiments, the best glass compositions are as follows: 80% palm ash, 10% kaolin and 10% feldspar or 10% dolomite while the suitable temperature being used for sintering process to produced end product is range between 1150°C to 1200°.

Simple technique for fabrication of Nd-phosphate laser glass rods for high power lasers

A technique for fabrication of Nd-glass laser rods from raw laser glass slab is presented. Cylindrical laser glass rods are prepared by using custom made glass sawing, milling and edging machines. A square section bar of laser glass, which is sawn from the slab, is converted to that with octagonal section by flat milling of the four corners of the square section bar. The rod with octagonal section is then transformed to a rod with right circular section in a glass edging machine. A ball-bearing based setup, which can be attached to the oscillatory arm of a conventional polishing machine, for simultaneous polishing of the flat end faces of a number of laser rods fixed in holders, is described. The method is suitable for fabrication of both large and small diameter laser rods.

Intrinsic dosimetry of glass containers: a potential interrogation tool for nuclear forensics and waste management

Intrinsic dosimetry is the method of measuring total absorbed dose received by the walls of a container holding radioactive material. By considering the total absorbed dose received by a container in tandem with the physical characteristics of the radioactive material housed within that container, this method has the potential to provide enhanced pathway information regarding the history of the container and its radioactive contents. We report the latest in a series of experiments designed to validate and demonstrate this newly developed tool. Thermoluminescence (TL) dosimetry was used to measure dose effects on raw stock borosilicate container glass up to 70 days after gamma ray, X-ray, beta particle or ultraviolet irradiations at doses from 0.15 to 20 Gy. Two main peaks were identified in the TL glow curve when irradiated with 60Co, a relatively unstable peak around 120 °C and a more stable peak around 225 °C. Signal strength of both peaks decayed with time. The minimum measurable dose using this technique is 0.15 Gy, which is roughly equivalent to a 24 h irradiation at 1 cm from a 50 ng 60Co source. As a result of fading, this dose would be detectable for approximately 1 year post-irradiation. In a more detailed analysis, the TL glow curves were separated into five peaks centered near 120, 160, 225, 300, and 340 °C. Differences in TL glow curve shape and intensity were observed for the glasses from different geographical origins. These differences can be explained by changes in the intensities of the five peaks. This suggests that mechanisms controlling radiation induced defect formation from gamma, beta, X-ray, and UV sources may be similar.

SEM-EDS analysis of ancient gold leaf glass mosaic tesserae. A contribution to the dating of the materials

Metal leaf (gold, silver or their alloys) glass tesserae began to be used in wall mosaics in the first century AD (the first examples are in Rome) and their use has been uninterrupted up to day.The metal leaf could be obtained from circulating coins, jewellery or refining. According to various techniques that have changed over the centuries, the leaf was hot fixed between two glass layers.From an archaeological point of view, it is interesting to know when and where these tesserae were made, if they were new made or if they were reused tesserae recovered from earlier dismantled mosaics.The determination of the glass composition of the tesserae is not of great help in this connection, for the same kind of glass was used over long periods. Available information is still scanter for glasses produced between the 1st to 8th centuries when the batch of raw materials (a natural soda called natron and a silica-lime sand) was melted in large tank furnaces and chunks of raw glass were transported all over the Mediterranean to be remelted and shaped into manufacts in small pot furnaces.The SEM-EDS analysis is proposed in this study as a useful tool to investigate the composition of both the glass and the gold alloy in leaf tesserae from mosaics of the 1st - 9th centuries. The comparison of the composition of the gold leaf of the tesserae with that of circulating gold coins (for which an important analytical data base is available), adds further information to the glass analysis, allowing us to improve the dating of the tesserae and increase the knowledge that may result from scientific analyses. The results demonstrate that good quantitative analyses of the metal leaf can be performed and that metal leaves made of pure gold or gold-silver alloys were used.

Influence of ultra-high residual compressive stress on the static and dynamic indentation response of a chemically strengthened glass

Abstract The influence of ultra-high surface compressive stresses (∼1 GPa) on the static and dynamic indentation response was investigated on an ion-exchanged glass and compared with the raw glass properties. Static hardness measurements were conducted utilizing a standard Vickers hardness tester (15 s duration), while dynamic hardness measurements were performed using a custom-made dynamic indentation hardness tester (60 μs duration). It was found that there is an 11% increase in static and dynamic hardness from the raw glass to the strengthened glass due to chemical strengthening. The dynamic hardness on the strengthened glass was also 23% greater than the static hardness. Additionally, the strengthened glass exhibited notable radial crack suppression. To examine the subsurface hardness profile, static Vickers indentations were conducted on a lateral surface which was polished to remove the strengthened layer. The hardness profile revealed that the effect of strengthening extended to 3 times the case-depth measured using photoelasticity.

Isotope analysis of English forest glass from the Weald and Staffordshire

Glass is one of several early modern industries where the development from small-scale workshop to large-scale industry offers a valuable insight into wider socio-economic trends. Previously, medieval and early modern forest (wood ash) glass has been studied using a range of analytical techniques. However, characterisations of production centres and exchange systems for forest glasses are difficult to verify, in part because very few examples of raw glass from furnace sites have been investigated. Compositional analysis can provide evidence for the raw materials used and can sometimes provide compositional groupings specific to sites. However, strontium and neodymium isotope determinations can actually provenance the glass by linking the geological ages, or sources, of raw materials to production sites. Using EPMA fifty-six raw glass samples from four sites in two English production areas in operation during the 14th and 16th centuries have been analysed. These analyses have shown that the main products of these sites were potash-rich, wood or bracken ash glasses. However, the chemical composition does not provide sufficient resolution to identify differences between the two English regions or the sites within these regions. A subset of five raw glass samples from each of these sites have also been analysed using TIMS to determine strontium and neodymium concentration and isotope ratios. The results allow glasses produced in each region to be differentiated, and can even be used to divide glass production sites within the regions.

Stabilizing the spectral properties and technologies of glass

Sheet glass from different manufacturers or the same manufacturer but produced in different periods differ by color hue and total light transmission, which depends not only on the total content of iron oxide in the raw material and glass but also on the displacement of the equilibrium Fe(II) ⇄ Fe(III). To ensure that the molten glass, technological process, and shaping are all of high quality the equilibrium state of different forms of iron must be stabilized. Concrete recommendations on stabilizing the equilibrium and monitoring the technological process are presented.

Supply routes and the consumption of glass in first millennium CE Butrint (Albania)

Archaeological, historical and analytical evidence can identify trade patterns and the movement of people and products and thus reveal the cultural and economic connections that existed at a given time. In the case of first millennium CE glass, the manufacture of raw glass in a limited number of glass making installations with unique compositional characteristics makes it possible to trace the likely origin of the raw materials at consumption sites. In this way the analytical characterisation of a large corpus of glass finds can identify changes in the supply routes of high-end industrial products from the Roman to the middle Byzantine period. Through the chemical analysis of a comprehensive glass assemblage from first to eighth century Butrint (Albania), the continuity and discontinuity of the supply of glass is traced at this consumption site. Ancient Butrint is located at the crossing point of late antique maritime trade routes, and this is reflected in the city’s archaeological record that includes a large number of glass artefacts as well as evidence of secondary glass working. The compositional analysis of glass samples from different archaeological contexts at Butrint revealed a great complexity as regards the base glass compositions. At least six sub-groups of soda-lime-silica glass can be distinguished that correspond to different identified primary glass production groups including Roman, HIMT and Egypt II glasses. Notably, one sub-group (WD2) among the Butrint fragments displays close proximity to other early medieval glass from central and northern Europe, whose precise place of origin is yet to be established. Chronological variations suggest a change in the supply of raw glasses with a dominance of Egyptian glass types during the early medieval period.

Synthesis and application of a novel molecularly imprinted polymer‐coated stir bar for microextraction of triazole fungicides in soil

The preparation, characteristics and application of a sorptive stir bar coated with molecularly imprinted polymer (MIP) using triadimefon as the template molecule are described here. Raw glass capillary was coated with MIP through chemical bonding. The synthesis method was effective and reproducible with the batch-to-batch RSD within 7.8%. Scanning electron micrographs of the stir bar revealed a highly porous coating with average thickness of 15 μm. The synthesized stir bar was proved to be highly stable in most of the solvent for use. Extraction performance showed the fabricated stir bar has excellent molecular recognition abilities for triadimefon and the structure-related compounds, such as triadimenol, diniconazole, flutriafol, hexaconazole, tebuconazole, paclobutrazol and uniconazole, and thus can be applied for simultaneous determination of these triazole fungicides from complex samples by coupling with high-performance liquid chromatography. The variables that influence extraction were optimized with 10.0 μg/L standard solutions of triazole fungicides, and the analytical method was established for the determination of triazole fungicides in soil. The detection limits were in the range of 0.14-0.34 μg/L, and the recoveries were from 86.7 to 114.6% for spiked soil sample.

Effective utilization of waste cathode ray tube glass—Crystalline silicotitanate synthesis

A novel process for crystalline silicotitanate (CST) synthesis was developed using waste cathode ray tube (CRT) panel glass as silicon source. The key trait of the process was to extract most of the silicon out of the glass for CST preparation, but leave Ba and Sr in the residue which had the potential to be employed as raw material for metallic Ba and Sr metallurgy. In the synthesis process, waste CRT panel glass was firstly treated by supercritical water (SCW)–NaOH solution for Si extraction, then sol–gel and hydrothermal treatments were used for CST preparation. 80% of Si in the glass could be extracted into the solution, while Sr and Ba were enriched in the residue in the form of Sr 2SiO 4 and Ba 2Si 3O 8, respectively. Sr and Ba contents in the residue were 2–3 times higher than those in the raw glass. SEM, XRD and TEM results indicated that CST was successfully synthesized. Ion exchanging experiments showed that the batch distribution coefficient of the synthesized CST to Cs + was up to 1.2 × 10 4 mL/g at pH 0.26.