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Despite decades of research into faience artefacts in China, many questions remain about how, where and by whom this technology began. This study combines published and new results of chemical analysis, morphology and chronology of the earliest faience beads uncovered from Xinjiang, Qinghai, Gansu, Shaanxi and Shanxi to suggest that at the latest in the mid-second millennium BC faience was first imported from the northern Caucasus or the Steppe into Xinjiang. In the second half of the second millennium, the Kayue people in Qinghai began making high potash faience, before the Zhou people in Shaanxi and Shanxi learnt and distributed the technology more widely across central China, probably via contacts with their pastoralist neighbours. [ABSTRACT FROM AUTHOR]

Based on the results of scanning electron microscopy (SEM) with energy dispersive X-ray spectrometry (EDX), about 20 faience beads from several cemeteries discovered since 1970 in China were studied chronologically and typologically. Faience beads excavated in China can be classified into two groups, chemically by composition, and by periods and provenance as: soda-enriched made somewhere on the route from Egypt to central China (11–10th century BCE); and potash-enriched made in China (middle Western Zhou to Eastern Zhou). According to the continuous matrix of inter particle glass (IP glass) and inner micro-structure, the difference between soda- and potash-enriched faience beads was identified, even though the IP glass was badly preserved. The faience beads with potash-enriched glaze and high copper content were in a better state of preservation than those with soda-enriched glaze because of their tight inner structure. [ABSTRACT FROM AUTHOR]

Beads and pin heads made of glassy faience , often decorated with true glass , discovered at seven different cemetery sites in Poland and dated chiefly to the Hallstatt C period (c. 750/700–600 BC), were examined by the LA-ICPMS and EPMA methods. The analysis involved 48 samples from 39 objects. The main objectives were: (i) to characterize the glassy faience in terms of the physical structure and chemical composition of the glass; (ii) to evaluate differences in the chemical composition of the glass forming the glassy faience; (iii) to examine the chemical composition of the true glass in the decoration on objects made of glassy faience. Glassy faience was found to be made of glass and numerous quartz grains, inclusions and gas bubbles. Manifest in the true glass of the decoration were numerous minor inclusions of the colorant, represented mostly by a compound of lead and antimony. Two groups of glass forming glassy faience were distinguished based on the differences in chemical composition: LMMK and LMGGF. The first is characterized by a moderate concentration of K2O (average 2.7%), high Al2O3, Fe2O3 and some trace elements (e.g. B and Ti). The second has a generally lower content, compared to LMMK, of K2O, Na2O, Al2O3, Fe2O3, B2O3 and TiO2, but higher PbO and Sb2O5. True glass LMG contained little K2O, Al2O3, B2O3 and TiO2, but a large amount of PbO and Sb2O5. All of the glasses had a low content of CaO and MgO. LMMK glass was melted using sand and a flux that could not be easily identified (plant ash?), whereas LMGGF and LMG glass used sand and natron. The glassy faience is usually blue and was colored with cobalt compounds. The yellow glass of the decoration was colored with lead antimonate. [ABSTRACT FROM AUTHOR]

Abstract: The paper presents the first results of a long-term project aiming to reconstruct the production technology of the Anabaptist (Hutterite) tin-glazed ceramics produced in Eastern-Central Europe. Microanalytical investigations were performed on 17th-century faience artefacts (six samples) excavated at Sárospatak, North-East-Hungary. The results are compared with analytical data on the direct or indirect precursor, Italian maiolica. The studied Hutterite faience artefacts reveal similarities with Italian maiolica. Calcareous clay with 14–22 wt% CaO was used for the buff-coloured ceramic body. Up to about 400 μm thick, tin-opacified white and blue lead-alkali glaze was applied on the biscuit-fired body. The glaze suspension contained sand admixture and a significant amount of common salt and was not fritted before application. The colorants used for the ceramic colours are lead antimonate for yellow, cobalt with arsenic, nickel and iron for blue, copper for green and manganese with minor iron for black. The ceramic colours were applied on the unfired glaze and maturing occurred during the second firing. The main technological difference when compared with the Italian Renaissance maiolica is the deliberate use of a high amount of tin oxide (17–20 wt% SnO2) together with 18–28 wt% PbO content for white glaze of the studied Hutterite faience. [Copyright &y& Elsevier]

Abstract: The microstructure and chemical composition of eight faience beads from an early Iron Age (12th century BCE) assemblage found in the ancient city port of Ashkelon (Israel) are determined by means of FTIR spectrometry, pXRF, microRaman and SEM-EDS analysis. The results are compared with published data of Egyptian and Near Eastern artifacts. Each sample exhibits a hue which is obtained by adding a specific colorant to the glazing mixture. A new gray chalcopyrite-manganese-based colorant was identified. Cementation glazing was most likely used in the manufacturing process of the specimens analyzed, except for the blue bead, which is an Egyptian blue frit. The results suggest that these objects represent a unique assemblage, quite different from contemporary Egyptian and Near Eastern materials, and provide new information regarding the Iron Age faience evidence in the southern Levant. [Copyright &y& Elsevier]

Abstract: Optical Coherence Tomography (OCT) is a non-invasive subsurface 3D imaging technique based on the Michelson interferometer. The non-invasive nature of OCT and its speed of acquisition makes it possible to image large volumes of intact objects to yield a complete overview of the microstructure. The production methods for ancient Egyptian faience were first investigated using scanning electron microscopy (SEM) imaging of the microstructure in polished sections and microprobe analysis of the composition of the glass phases. These studies were based on original Egyptian faience objects and laboratory reproductions of faience beads made using three different production methods. The microstructure of the same laboratory samples and the Egyptian faience objects from the British Museum Research Laboratory Collection are re-examined using OCT. It is found that OCT virtual cross-section images can be used to group ancient faience objects into three categories on the basis of the morphology of the surface glaze layer and the glaze/core interaction layer. The OCT images correspond well with SEM images of polished sections of ancient faience objects and laboratory reproductions. The virtual cross-sections produced by OCT are somewhat limited by the penetration depth, which is affected by the high absorption coefficient of the material and, therefore, cannot always provide information on the presence or absence of interparticle glass that binds together the quartz particles in the core. Nevertheless, the top two layers are well imaged and since OCT images can be obtained rapidly and without the necessity of removing a sample, the method can be applied to a very much wider range of ancient faience objects than is possible by SEM examination of polished cross-sections. In summary, this paper examines to what extent OCT can assist the investigation of the production techniques of ancient Egyptian faience. [Copyright &y& Elsevier]

Abstract: Cobalt-blue colorant was first used in the 18th Dynasty in the New Kingdom of Egypt. The source of this cobalt was cobaltiferous alum from the Western Oases of Egypt. The use of this alum, especially in glass, was suddenly limited at the end of the 18th Dynasty. There is little evidence of the production of cobalt-blue glass in the Ramesside Period (the 19th–20th Dynasties) in the New Kingdom of Egypt. In this study, we brought a portable X-ray fluorescence spectrometer to two archaeological sites located in the Memphite region and used it for onsite analyses of Ramesside cobalt blue-colored glasses and faiences. This method revealed that the compositional characteristics of the cobalt-blue colorant in these Ramesside glasses and faiences is different from the colorant derived from cobaltiferous alum used in the 18th Dynasty, based on the comparison of transition metal composition and alumina content with those of the cobalt blue-colored artifacts from the 18th Dynasty. This result suggests that a new cobalt source other than cobaltiferous alum from the Western Oases was utilized in Egypt during the Ramesside Period. [Copyright &y& Elsevier]

Abstract: In cementation glazing, for various reasons, there are significant differences between the composition of the glass phases present in the faience microstructure and the glazing powder composition. Furthermore, in this glazing method, the glazing powder should perform more functions, which are: producing a shiny and smooth glaze coating, producing a firm capsule surrounding objects entirely (to prevent adhesion between sintered glazing mixture and the melting glaze coating), and, finally, producing a porous and friable sintered glazing mixture for safe and easy removal of buried objects. It is obvious that these functions also have significant effects on the glazing powder composition and constitution. Therefore, analytical data on faience glass phases are very unlikely to reflect the strict composition and constitution of the original glazing powder properly. Accordingly, the composition and constitution of cementation glazing powder have remained obscure for a long time. These data are particularly crucial factors for cementation replication experiments and, consequently, for our awareness of the ancient faience production. In this paper, a series of cementation replication experiments have been conducted in an attempt to provide further clarification of these issues. In addition, as a comparative indicator for alkali and copper vaporisation, a small piece of rock quartz was placed separately above the glazing powder. After firing, the appearance of the faience objects and quartz pieces and the microstructures and chemical compositions of a select group of samples, obtained using Scanning Electron Microscopy – Energy Dispersive Spectroscopy (SEM-EDS), were investigated. The discussion has focused mainly on issues such as the raw materials and their contribution in the glazing process, the criteria for determining the faience glazing methods, the necessary quantity of alkalis for a successful cementation glazing, and, particularly, the glazing mechanism. [Copyright &y& Elsevier]

Abstract: The microstructures and chemical compositions of some 15 faience objects from Crete spanning the period from Middle Minoan IIIA through to Late Minoan IA are determined using analytical scanning electron microscopy. The Minoan faience is compared with replicate faience beads produced in the laboratory using various combinations of manganese, copper and iron as colorants. The alkali contents of the replicate beads are varied so that the colorants are present both as ions in a glass phase and as particulate oxides. These data are then used to try to infer the original colour of the Minoan faience, the great majority of which has suffered severe weathering during burial. The results suggest that instead of the present day “hallmark greys and browns” and “subtle greens and blues”, Minoan faience originally exhibited a wide range of colours, including bright turquoise blue, purple and violet, and pale yellow-green and greenish turquoise. [Copyright &y& Elsevier]

Abstract: The chemical compositions and microstructures of some 35 faience objects from Egypt spanning the period from the Middle Kingdom through to the 22nd dynasty are determined using analytical scanning electron microscopy. Replicate faience beads glazed in the laboratory using the efflorescence and cementation methods are similarly investigated. In efflorescence glazing, there appears to be preferential efflorescence of soda over potash, and in cementation glazing, preferential take up of potash over soda into the glaze. These data are then used to try to infer the raw materials and methods of glazing employed in the production of the ancient faience. The glaze/glass phases present in the faience differ significantly in composition from that of New Kingdom glass. This could be due either to the use of different plant ashes or to changes in the composition of the plant ashes during the production of faience and/or glass. Although it is only rarely possible to determine with certainty whether ancient faience was glazed by efflorescence, cementation or application, the observed microstructures provide an indication of the approach adopted to achieve desired performance characteristics such as strength. [Copyright &y& Elsevier]

Abstract: Soda-rich plant ashes have been used in the Near East and Egypt in the production of glass and faience from the 4th millennium BC onwards, and mixed alkali plant ashes have been similarly used in western Europe during the 2nd and first half of the 1st millennia BC. In the production of these ashes, the plants of interest are salt resistant, halophytic plants of the Chenopodiaceae family, growing in coastal, salt marsh and desert regions. A primary criterion in selecting ashes for glass and faience production is that the alkalis are predominantly in the form of carbonates, bicarbonates and hydroxides rather than either chlorides or sulphates. In the current paper, previously published data for such ashes are brought together and re-assessed, and new analytical data are presented for ashes produced from plants collected in Egypt, Greece and the UK. For the ashes produced from Salsola kali plants collected from Greece and the UK, the soda to potash ratios (0.3–1.8) do not show any systematic differences between the regions in which the plant was growing, but instead reflect the fact that this species favours the accumulation of K+ over Na+ ions. Further, the results suggest that S. kali could have been the source of the mixed alkali ashes used in western Europe, if the ashes had first been treated in some way in order to reduce their lime-plus-magnesia contents. [Copyright &y& Elsevier]

Abstract: Natron deposits, the best known of which being those at Wadi Natrun in Egypt, have been used as the flux in the production of vitreous materials from the early 4th millennium BC onwards. In the present paper, the history of the use of natron as a flux is traced from its beginnings in the glaze of Badarian steatite beads, through its use in glass production starting in the 1st millennium BC, until its apparent shortage during the 7th to 9th centuries AD, and its subsequent replacement by plant ash during the 9th century AD. Documentary evidence for possible natron sources in Egypt, including the Wadi Natrun, and around the eastern Mediterranean is summarised, and the results of recent fieldwork at the Wadi Natrun and at al-Barnuj in the Western Nile Delta are presented. The possible reasons for the apparent shortage of natron from 7th to 9th centuries AD and its subsequent replacement by plant ash as the flux used in glass production during the 9th century AD are then considered. These include the possibility that, because of the massive scale of glass production, the demand for natron exceeded its supply; the possible effect of climatic changes; and the potentially disruptive role of political events in the Wadi Natrun–Delta region. [Copyright &y& Elsevier]

This paper presents compositional results for six faience beads from Adunqiaolu, an Early Bronze Age site in western Xinjiang, China. It is shown that all analysed samples were made of mixed-alkali flux with sodium oxide 8–10% and potassium oxide 5–9%. The microstructure of samples indicates that cementation glazing was used. The analytical results, together with the typology of the faience beads were then compared with data of Bronze Age faience beads found in Europe and East Asia. There are clear similarities in both typological and technological features. As the earliest faience objects discovered in China so far, the Adunqiaolu beads set an essential starting point for the further discussion on the early exchange network evidenced by faience products and long distance transmission of technologies and knowledge. This observation is of significance for deepening our understanding of prehistoric exchange between West and East across the Eurasian continent by providing another element in addition to metallurgy, cereal crops and herding animals. • Earliest faience beads in China analysed by SEM and EPMA. • Mixed-alkali glaze composition and typology indicate origin from the West. • Import of faience objects as part of wider package of cultural contact West-East. • Precursor for faience production in China using local materials and recipes. [ABSTRACT FROM AUTHOR]