Yellow Glass Research Articles

Visible/solar light active transparent BiB3O6 glass- ceramics multi-catalysis

Borate based non-centrosymmertic crystals are known for their non-linear optical properties. This study reports BiB3O6 glass-ceramics for photocatalysis and piezocatalysis applications. These were fabricated via. melt-quench technique and yellow transparent glass samples were made. Effectiveness of a bismuth-triborate glass-ceramic (BiB3O6) in degrading methylene blue (MB) and methyl violet (MV) dye undergoing photocatalysis in the presence of visible light and solar light for MB dye was studied. Degradation observed in photocatalysis was ∼62 % and ∼50 % for MB and MV dye respectively in 240 min whereas, ∼72 % of MB dye was degraded under solar light. Piezocatalysis was examined to assess the extended potential of this material, resulting in approximately ∼76 % degradation of MB dye. Moreover, in synergistic photo-piezocatalysis degradation of ∼88 % was observed. Phytotoxicity was also assessed using the germination index (GI) showing ∼76 %, using heat treated sample.

Dy-Al-Ce codoped silica: a promising yellow laser glass with enhanced resistance to X-ray-induced photodarkening

To develop Dy doped silica glass with a higher irradiation resistance, which can be adapted to high power violet or blue LD pumped yellow laser fibers, the designed Dy-Al-Ce codoped silica glasses, 0.05Dy2O3-1.5Al2O3-xCe2O3-(98.45-x)SiO2 (x = 0, 0.05, 0.1, 0.25, 0.5), were prepared by the sol-gel method. Their excitation spectra, emission spectra and emission decay curves associated with the yellow emission from 4F9/2 to 6H13/2 of Dy were determined before and after the X-ray irradiation of 1000 Gy. The relation between these spectra and Ce-codoping concentrations is discussed, including the sensitization from Ce to Dy, the reverse energy transfer from Dy to Ce, and especially the X-ray-induced photodarkening, which is detrimental to the 576 nm yellow emission of Dy. The centers that cause the photodarkening are analyzed by electron paramagnetic resonance and radiation induced absorption spectra. It is found that Ce can effectively suppress the Al-oxygen hole center induced by the X-ray across the entire concentration range of Ce-codoping, but a new photodarkening center is generated at higher concentrations of Ce-codoping. Finally, the optimized Ce-codoping concentration of ∼0.1 mol% is used to achieve a promising yellow laser glass of Dy-Al-Ce codoped silica with enhanced irradiation resistance, resulting in its X-ray-induced photodarkening that is only 6% - 14% of that in the Ce-undoped.

Changes in standing stability when wearing different colored glasses cannot be determined by participants’ subjective preference – A crossover randomized single-blinded pilot study

BackgroundThe use of individually preferred colored glasses has gained popularity with the expectation that it may improve balance control and sports performance, however, the results of previous studies remain inconclusive. Aim of the studyIn the present pilot study, we aimed to determine the association between participants’ subjective preference and standing balance performance when wearing five different colored glasses. MethodsThirteen participants stood on one or two legs on a pair of synchronized force platforms for 30 seconds with 60 seconds rest between the five-five randomized stance trials, while wearing red, blue, yellow, green, or transparent colored glasses. In addition to 7 CoP-related variables, we analyzed five features of EMG data from three lower limb muscles on both legs. ResultsNo significant effect of colored glasses was found. Some CoP (velocity: χ²(4, 13) = 10.086; p = 0.039; Kendall’s W = 0.194, root mean square [RMS]: χ²(4, 13) = 12.278; p = 0.015; Kendall’s W = 0.236) and EMG-related (RMS of biceps femoris: χ²(4, 13) = 13.006; p = 0.011; Kendall’s W = 0.250) variables showed differences between the colored glass conditions during dominant-leg stance, however, participants failed to consecutively determine these differences in standing stability. ConclusionsOverall, our results may suggest that lens color preference, irrespective of the color itself, may influence dominant leg standing balance most probably due to psychological factors, however, only subjective determination have no potential to determine the color of the glasses that would support the individual’s standing balance the most.

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.

Tenedos Nekropolisi’nden Cam Pendant

The male head-shaped glass pendant discussed in this study was found together with a terracotta statuette, a terracotta head (or a protome), and some knucklebones (astragali) in a pithos burial during rescue excavations in 1993 in the Tenedos necropolis. The rod-formed pendant has a beard, big eyes, a long nose, full lips, and a slightly protruding chin. Trails of opaque yellow, white, and turquoise glass were applied to the translucent dark blue body of the pendant. Such glass pendants are considered to be of Phoenician and/or Punic origin and are distributed throughout the Mediterranean basin, the northern coast of the Black Sea, and Eastern Europe. They range in date from the 7th century to the middle of the 1st century BC. The Tenedos glass pendant is compatible with M. Seefried’s “Type C” (male head with curly hair) and dated between the 5th century and 3rd century BC. It belongs to the C1 subgroup (head with curly hair and sleek beard) of this type. The head-shaped glass pendant is a rare find from the northeast region of the Aegean. In the context of the other finds from the tomb, notably the standing female figurine, the glass pendant can be said to belong to the first half of the 5th century BC. Moreover, this find indicates the contact between the Phoenician and/or Punic world and Tenedos in this period.

The production technology of mineral soda alumina glass: A perspective from microstructural analysis of glass beads in Iron Age Taiwan.

Mineral soda alumina (m-Na-Al) glass is a common glass production group found around the Indo-Pacific region. In Iron Age Taiwan, its presence dates back to the early 1st millennium AD. This research discusses m-Na-Al glass beads excavated from Iron Age sites in Taiwan. No production sites for m-Na-Al have been found, but microstructural analysis suggests m-Na-Al glass appears to originate around South Asia and is exchanged widely. SEM-EDS and EPMA were used to analyse red, orange, yellow, green and blue m-Na-Al glass. The microstructure of the glass shows the presence of plagioclase and alkali feldspar relics in the glass, suggesting a low manufacturing temperature. Copper-based colourants are identified in red, orange, blue and green glass, while lead tin oxide is used in yellow and green glass. It appears that various types of copper-containing raw materials were procured by craftspeople, and a self-reduction process for producing red and orange glass is tentatively proposed. Additionally, the microstructure of yellow glass reveals different colouring paths were used. These results increase our understanding of the selection of raw materials, and provide an impetus for further research on the cross craft interaction between glass and copper production.

Glass-based pigments in painting: smalt blue and lead\u2013tin yellow type II

Glass-based pigments have an important role in the panorama of artistic production due to the fact that their manufacturing processes involve a combination of different skills and understanding, and they have a role in disciplines ranging from glass technology to metallurgy, from glazed ceramic to stone imitation and from vitreous mosaic tesserae to painting materials. The main goal of this manuscript is to present a critical review of the literature relating to blue smalt and “yellow glass” (lead–tin yellow type II) pigments: presenting their historical background, the analytical protocol, the processes of alteration and decay and finally tracing issues. Several case studies analyzed by the authors will be presented. Particular attention was devoted to the correlation between micro-textural features and decay processes affecting the studied pigments, though the widespread heterogeneity of the analyzed materials and the variability of the artistic techniques in which the pigments were used as well as the effect of the relevant (micro-)environmental conditions dictate a cautious approach. These studies are presented in the context of information about the chain of production, the selection of the raw materials and relevant provenance studies.

Color Glass by Layered Nitride Films for Building Integrated Photovoltaic (BIPV) System

We investigated layered titanium nitride (TiN) and aluminum nitride (AlN) for color glasses in building integrated photovoltaic (BIPV) systems. AlN and TiN are among suitable and cost-effective optical materials to be used as thin multilayer films, owing to the significant difference in their refractive index. To fabricate the structure, we used radio frequency magnetron deposition method to achieve the target thickness uniformly. A simple, fast, and cheap fabrication method is achieved by depositing the multilayer films in a single sputtering chamber. It is demonstrated that a multilayer stack that allows light to be transmitted from a low refractive index layer to a high refractive index layer or vice-versa can effectively create various distinct color reflections for different film thicknesses and multilayer structures. It is investigated from simulation based on wave optics that TiN/AlN multilayer offers better color design freedom and a cheaper fabrication process as compared to AlN/TiN multilayer films. Blue, green, and yellow color glasses with optical transmittance of more than 80% was achieved by indium tin oxide (ITO)-coated glass/TiN/AlN multilayer films. This technology exhibits good potential in commercial BIPV system applications.

Thirteenth-century stained glass windows of the Sainte-Chapelle in Paris: An insight into medieval glazing work practices

The restoration of the four northern windows of the 13th century Sainte-Chapelle in Paris from 2011 to 2014 has offered a unique opportunity to investigate the chemical composition and color of medieval glasses. This impressive corpus, covering a total surface of 660 m2, was created in a record time of a few years. The glasses from ten selected panels were analyzed using non-destructive and non-invasive techniques, with a specific consideration for the color of the glasses. Ion beam analyses performed at the New AGLAE facility enabled revealing that all ancient glasses are “potash” type glasses made from plant ashes, likely beech, in agreement with previous results on off-site panels. The multivariate analysis of major and minor elements demonstrates the presence of compositional clusters with a small variability suggesting the identification of bundles of glasses. The coloration of the glasses was measured by optical absorption spectroscopy, using a mobile spectrophotometer over the entire UV–visible-NIR energy range. The color palette is made of six colors assigned to typical medieval recipes. The chromophores of the different glasses are identified by combining the chemical composition, optical absorption spectroscopy and colorimetry. Colorless, yellow and purple glasses arise from the subtle redox equilibrium between manganese and iron. Their reduced usage shows their uncertain production. Blue glasses are colored by Co2+ using saffre from the contemporary German mines, green glasses are colored by Cu2+ and Fe3+ using high concentrations of copper and red glasses are striated glass colored by metallic copper nano-particles. Glass matrix and chromophores form compositional clusters, which are spread among the panels of the four windows suggesting that the glazing of these four windows was run simultaneously by the same atelier using the same supply of glass.

Glass beads from Guishan in Iron Age Taiwan: Inter-regional bead exchange between Taiwan, Southeast Asia and beyond

Archaeological excavations at Guishan in the southern end of Taiwan have recovered more than a hundred glass beads dating to mid-1st millennium CE. This research investigates the exchange of glass beads between Guishan, eastern Taiwan and Southeast Asia, by analysing the styles, chemical composition and microstructure of 64 glass beads from Guishan, using SEM-EDS, EPMA and LA-ICP-MS. The findings suggest that beads with an m-Na-Al glass and v-Na-Ca composition are the most common, supporting evidence for bead exchange between Guishan and Southeast Asia, originated in South Asia and Western Asia. Furthermore, most m-Na-Al glasses were coloured by copper, and different types of copper-based additives may have been used for different colours, indicating the beads may be derived from multiple production centres or workshops via Southeast Asia. Conversely, the glass bead compositions suggest that glass bead exchange between other contemporary sites in Taiwan is less evident at Guishan, except for one type of yellow glass bead containing bone ash which is different. This bone-ash containing yellow glass at Guishan is firstly identified in Iron Age Taiwan as well as around the South China Sea region. Its counterparts are also found from archaeological sites in southeastern and coastal eastern Taiwan, which might indicate small scale glass bead exchange. This evidence together suggests a dynamic glass bead exchange network between Guishan, eastern Taiwan, Southeast Asia and beyond.

Vitreous Tesserae from the Four Seasons Mosaic of the S. Aloe Quarter in Vibo Valentia–Calabria, Italy: A Chemical Characterization

This work reports the results of the archaeometrical investigation performed on twenty glass tesserae collected in 2018, during the restoration of the Four Seasons mosaic, which dates between the second and the third century AD, in the archaeological area of the S. Aloe quarter in Vibo Valentia (Calabria, Italy). The coloured glass tesserae were analysed through a micro-analytical approach using an Electron Probe Micro Analyser with Wavelength-Dispersive Spectroscopy (EPMA-WDS) and Laser Ablation with Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS). The aims of the study were (1) the determination of the chemical composition and the technology of glass mosaic tesserae production; (2) the individuation of colouring and opacifying agents used for the production of the glass tesserae. The glasses show the typical soda–lime–silica composition. EPMA-WDS results prove the use of Sn–Pb antimonates to create yellow glass, and of cuprite to obtain the red colour. Copper and cobalt were employed in both green and blue glasses to produce different shades of colour (grey, tints of green, dark and light blue).

Chemical and Petrographic Characterization of Stone and Glass Tesserae in the Nereid and Geometric Mosaics from the S. Aloe Quarter in Vibo Valentia–Calabria, Italy

Vibo Valentia’s S. Aloe quarter is an archaeological area which has three beautiful mosaic floors, dated between the centuries I BC and V AD. This work reports the results obtained on 22 glass and stone tesserae collected from the Nereid and Geometric mosaics during a recent restoration of the site. The analyses were carried out through a multi-analytical approach. The petrographic study of the stone tesserae was carried out using polarizing optical microscopy while the geochemical one was conducted using two micro-analytical techniques: the electron probe micro-analyzer with energy-dispersive X-ray spectrometry and a combination of laser ablation with inductively coupled plasma mass spectrometry for determining the major, minor, and trace element concentrations. The research highlights the use of different kinds of stones such as marble, volcanic, and sedimentary rocks. The glasses show the typical soda–lime–silica composition indicating the use of natron as a flux. The trace element concentrations prove the use of Pb-antimonates to create yellow glass. The bronze scrap was used to obtain the green color, while cobalt and copper were used to obtain different gradations of blue. These results confirm the high technological level reached by glassmakers in the Imperial Age, thus highlighting the importance of the S. Aloe archeological site.

Improvement of functional performance of concrete in livestock buildings through the use of complex admixtures

When examining concrete in livestock buildings, signs of corrosion and destruction of concrete floors and walls were found. Experimental studies have identified main critical points that directly affected concrete continuity. Excessive moisture, use of corrosive acidic or alkaline disinfectants and presence of natural excretions of animals (urine and feces) were found in livestock buildings. To solve this problem, admixtures were proposed: yellow iron oxide pigment and liquid glass which improve strength characteristics of concrete, its heat resistance and reduce penetrability. It was proved by the conducted studies that introduction into concrete of admixtures in quantities from 0.5 % to 2 % has resulted in a 2.8 times smaller depth of chloride penetration as compared to the control specimens. This was due to a decrease in water absorption by concrete when introducing iron oxide, cuprous sulphate, peracetic acid and sodium silicate which reduced pore size in samples. It was proposed as an innovation to assess thermal stability of concrete using the method of temperature-programmed desorption mass spectrometry (TPMS) based on the dependence of evolution of carbon monoxide and carbon dioxide from samples of carbonate-containing substances on the sample temperature. Microbiological studies have identified microbes of Penicillium and Fusarium species, bacteria Escherichia coli and Pseudomonas aeruginosa, which cause corrosion of concrete in livestock buildings. Numerous experiments have shown that the proposed admixtures added to the concrete (based on yellow iron oxide pigment (1.5‒2.0 wt. %), peracetic acid (0.2‒0.3 wt. %), liquid glass (2‒3 wt. %) and cuprous sulfate (0.5‒1.0 wt. %) had antimicrobial properties and thus prospects for their use in animal husbandry

New scheme of LiDAR-embedded smart laser headlight for autonomous vehicles.

A new scheme of LiDAR-embedded smart laser headlight module (LHM) for autonomous vehicles is proposed and demonstrated. The LiDAR sensor was fabricated by LeddarTech with the wavelength of 905-nm, whereas the LHM was fabricated by a highly reliable glass phosphor material that exhibited excellent thermal stability. The LHM consisted of two blue laser diodes, two blue LEDs, a yellow glass phosphor-converter layer with a copper thermal dissipation substrate, and a parabolic reflector to reflect the blue light and the yellow phosphor light combined into white light. The LHM exhibited a total output optical power of 9.5 W, a luminous flux of 4,000 lm, a relative color temperature of 4,300 K, and an efficiency of 421 lm/W. The high-beam patterns of the LHMs were measured to be 180,000 luminous intensity (cd) at 0° (center), 84,000 cd at ± 2.5°, and 29,600 cd at ± 5°, which met the ECE R112 class B regulation. The low-beam patterns also satisfied the ECE R112 class B regulation as well. Integrating the signals received from the Lidar detection and CCD image by a smart algorithm, we demonstrated the generation of smart on/off signals for controlling the laser headlights. The recognition rate of the objects was evaluated to be more than 86%. This novel LiDAR-embedded smart LHM with the unique highly reliable glass phosphor-converter layer is favorable as one of the most promising candidates for use in the next-generation high-performance autonomous vehicle applications.

Reassessment of pre-eruptive water content of lunar volcanic glass based on new data of water diffusivity

Lunar volcanic glasses associated with mare basalt magmatism experienced significant degree of degassing, and to retrieve their initial water contents requires data of water diffusivity. We carried out diffusion experiments at 0.5 GPa and 1703–1903 K in a piston cylinder apparatus for two synthesized lunar basaltic melts with compositions corresponding to Apollo green glass and yellow glass. The water diffusion profiles measured by FTIR spectroscopy yield water diffusivities 0.5–1 order of magnitude greater than those of terrestrial basaltic melts, which is attributed to the difference in melt polymerization and modest contribution from H2 diffusion. However, hydroxyl (OH) is not only the dominant H species but is also inferred to be the major carrier of H in our experiments at oxygen fugacity estimated IW ± 1 (IW: iron-wüstite buffer). Modeling of previously reported profiles of volatile loss in an Apollo green glass bead using the new water diffusivity indicates an average cooling rate of 1–2°C/s and an initial water content of 120–260 μg/g. With the assumption of limited degassing before magma fragmentation, the lunar mantle source is inferred to contain 6–22 μg/g H2O. The lunar interior appears to be less hydrous the Earth's interior but still contains a considerable amount of water.

The Effect of Magnitude and Direction of Heat Flow on the Thermal Conductivity for Insulation Materials (Glass Wool) by Using Probe Method

The thermal energy of building is determined by the thermal properties of the materials and how to install these materials in the elements of buildings according to the direction of heat transfer. The effectiveness of thermal insulation (glass wool) is dependent on its thermal conductivity which is varies in different directions of fibers of glass wool. Glass wool is formed of fibers and binders tangled together during the industrial process to provide some elasticity. The experimental values of thermal conductivity of the insulation materials are changed according to magnitude of the heat power and direction of fiber arrangement. The thermal conductivity for insulation materials has been measured by using probe method, Huekseflux ® TP02 used to measure the thermal conductivity by emit the flow perpendicular and parallel to the fibers of glass wool. Two samples of yellow glass wool (density 68 kg/m3) with dimensions (10 ×10 ×30) cm have been used. Hot Disk bulk isotropic module has been used to evaluate thermal conductivity. TPS source (Hot Disk probe reference: 4922) characterized by a diameter of 14.61 mm has been selected. COMSOL® multiphysics axisymmetric 2D model has been used to follow the axial and the radial directions of the heat transfer.

A Study on the Provenance of an Opacifying Agent(PbSnO<sub>3</sub>) in Yellow and Green Glass Beads Excavated from the Korean Peninsula

The yellow crystalline material present in yellow and green glass beads excavated from sites in the Baekje region of Korea was previously analyzed through scanning electron microscopy with energy dispersive spectroscopy and X-ray diffraction, revealing that the yellow crystalline material was PbSnO3. This material is a pigment that is rarely seen in the Korean peninsula. Furthermore, some studies have been published on the provenance of lead in this material, which revealed no relationship to Korea, China, or Japan. In this study, we collected all accessible results of analyses on the lead isotope ratio of yellow and green glass beads excavated from the Korean peninsula, specifically from 7 sites in the Baekje region(located in the vicinity of Seoul, Wanju, Hwaseong, Osan, Gongju, Buyeo, and Iksan) and 2 sites in the Silla region(located in the vicinity of Gyeongju and Changnyeong). We subsequently investigated the lead provenance of the opacifying agents in the glass beads through comparison with the current extent of the galena data accumulated for the East Asian region, including Korea, China, and Japan, and for Thailand(Kanchanaburi Province), Southeast Asia. Our analysis determined that the lead provenance of the glass beads excavated from the Korean peninsula was Thailand(Kanchanaburi Province). Beyond our results, further studies should seek to determine the production sites of the glass beads. Obtaining and comparing the scientific analyses of glass beads from India and Southeast Asia would enable research on the glass beads trade through the maritime silk road. Key words: Yellow and green glass beads, Opacifying agent(PbSnO3), Provenance estimation, Baekje, Southeast Asia

Over the rainbow? Micro-CT scanning to non-destructively study Roman and early medieval glass bead manufacture

Desktop micro-CT scanner has become a standard piece of equipment for many materials science laboratories and is increasingly popular in the field of archaeology for the study of archaeological soils and small archaeological artefacts. The technique does have limitations which are reviewed. Then, the usefulness of desktop Micro-CT scanners for the study of archaeological artefacts is demonstrated in a non-destructive study of manufacturing methods of Roman and Early Medieval monochrome and polychrome glass beads. Differences in glass colours show up in these scans as differences in attenuation. The presence and distribution of bubbles and various inclusions (metal, opacifier) are also well visible. Shaft shapes and patterns of bubbles inside the glass make it possible in most cases to distinguish between drawn, wound and constructed (millefiori) beads and to study shaping methods. Shafts shapes also reveal shapes and dimensions of the mandrels used in bad manufacture. Decoration and construction methods are be visualized and studied in virtual cross-sections and semi-3D rendered images of selected glass colours. Visible degradation processes - including fissuring, leaching (especially of opaque yellow glasses) and dissolution processes - are highlighted. The micro-CT scans demonstrate how quality of raw glass, base design and workmanship ion bead manufacture have improved with time. Moreover, it shows how these scans may serve as basis to discuss the organization of workshops where simple or more complex objects were made from non-metallic raw materials, and the availability and distribution of different qualities of raw materials for these workshops.

Microcrystals of antimony compounds in lead–potassium and lead glass and their effect on glass corrosion: a study of historical glass beads using electron microscopy

Crystalline inclusions of antimony compounds in lead glass of the nineteenth century have been investigated by means of transmission electron microscopy, scanning electron microscopy, X-ray microanalysis, electron backscatter diffraction and microcathodoluminescence. Microcrystallites of orthorhombic $$\hbox {KSbOSiO}_4$$ (KSS) with the sizes ranging from about 200 nm to several micrometers have been detected in lead–potassium glass of turquoise seed beads prone to a glass disease causing the irrecoverable deterioration of beaded articles kept in museums. The KSS crystals have high number density and tend to form large colonies. Crystallites of cubic $$\hbox {Pb}_2\hbox {Fe}_{0.5}\hbox {Sb}_{1.5}\hbox {O}_{6.5}$$ have been detected in stable yellow lead glass beads. Their number density and sizes are much less than those of the KSS particles observed in turquoise glass; they do not form large clusters. We have come to conclusion that KSS precipitates are responsible for the internal strain-induced corrosion of turquoise lead–potassium glass eventually resulting in crumbling of beads to sand particles. The following scenario explains this phenomenon: $$\hbox {K}^+$$ and $$\hbox {Sb}^{5+}$$ used for glass doping form KSS crystallites during glass melting; tensile strain arising in the glass matrix during cooling because of difference in temperature coefficients of linear expansion of glass and KSS crystals gives rise to crack formation and in course of time results in glass falling apart to heterogeneous pieces. Small crystallites of $$\hbox {Pb}_2\hbox {Fe}_{0.5}\hbox {Sb}_{1.5}\hbox {O}_{6.5}$$ cannot induce a sufficient strain to break yellow lead glass, and internal cracks do not arise in this glass during its cooling. This may explain the stability of yellow lead glass.

Evidence for a sulfur-undersaturated lunar interior from the solubility of sulfur in lunar melts and sulfide-silicate partitioning of siderophile elements

Sulfur concentrations at sulfide saturation (SCSS) were determined for a range of low- to high-Ti lunar melt compositions (synthetic equivalents of Apollo 14 black and yellow glass, Apollo 15 green glass, Apollo 17 orange glass and a late-stage lunar magma ocean melt, containing between 0.2 and 25 wt.% TiO2) as a function of pressure (1–2.5 GPa) and temperature (1683–1883 K). For the same experiments, sulfide-silicate partition coefficients were derived for elements V, Cr, Mn, Co, Cu, Zn, Ga, Ge, As, Se, Mo, Sn, Sb, Te, W and Pb. The SCSS is a strong function of silicate melt composition, most notably FeO content. An increase in temperature increases the SCSS and an increase in pressure decreases the SCSS, both in agreement with previous work on terrestrial, lunar and martian compositions. Previously reported SCSS values for high-FeO melts were combined with the experimental data reported here to obtain a new predictive equation to calculate the SCSS for high-FeO lunar melt compositions. Calculated SCSS values, combined with previously estimated S contents of lunar low-Ti basalts and primitive pyroclastic glasses, suggest their source regions were not sulfide saturated. Even when correcting for the currently inferred maximum extent of S degassing during or after eruption, sample S abundances are still > 700 ppm lower than the calculated SCSS values for these compositions. To achieve sulfide saturation in the source regions of low-Ti basalts and lunar pyroclastic glasses, the extent of degassing of S in lunar magma would have to be orders of magnitude higher than currently thought, inconsistent with S isotopic and core-to-rim S diffusion profile data. The only lunar samples that could have experienced sulfide saturation are some of the more evolved A17 high-Ti basalts, if sulfides are Ni- and/or Cu rich.Sulfide saturation in the source regions of lunar melts is also inconsistent with the sulfide-silicate partitioning systematics of Ni, Co and Cu. Segregation of significant quantities of (non)-stoichiometric sulfides during fractional crystallization would result in far larger depletions of Ni, Co and Cu than observed, whereas trends in their abundances are more likely explained by olivine fractionation. The sulfide exhaustion of the lunar magma source regions agrees with previously proposed low S abundances in the lunar core and mantle, and by extension with relatively minor degassing of S during the Moon-forming event. Our results support the hypothesis that refractory chalcophile and highly siderophile element systematics of low-Ti basalts and pyroclastic glasses reflect the geochemical characteristics of their source regions, instead of indicating the presence of residual sulfides in the lunar interior.