Chinese painted enamel is an artistic tradition of enamelled copperwares developed during the Kangxi period (1662-1722), commonly referred to as Canton enamel after the Wade-Giles spelling of... Show moreChinese painted enamel is an artistic tradition of enamelled copperwares developed during the Kangxi period (1662-1722), commonly referred to as Canton enamel after the Wade-Giles spelling of Guangzhou. In this study, enamel fragments from areas of damage in the decorated surface of ten Chinese painted enamel objects dating to the 18th and early 19th century in the collections of the Ashmolean and Fitzwilliam Museums were nondestructively analysed with ESEM-EDX (Environmental Scanning Electron Microscopy - Energy Dispersive XRay Spectroscopy). After analysis, the enamel fragments were reattached to the objects using a conservation grade adhesive. Quantitative EDX elemental analysis is presented for the white enamel, underdrawings, eight painted enamel colours, outlines, and gilding. The enamel-glass composition, opacifier and colourants are discussed and compared to ceramic, glass, and enamelled metal technologies in use during the Ming Dynasty (1368-1644).The results show that Chinese painted enamels combine Chinese and European technology to create a new and distinct art form. Show less
Cloisonne-style motifs are rare and enigmatic in Chinese painted enamels because of their distinct technological development at the end of the 18th century. Five late Qianlong to Jiaqing period ... Show moreCloisonne-style motifs are rare and enigmatic in Chinese painted enamels because of their distinct technological development at the end of the 18th century. Five late Qianlong to Jiaqing period (1736-1820) Chinese painted enamels with cloisonne-style motifs are investigated using environmental scanning electron microscopy-energy dispersive X-ray spectroscopy. Back-scattered electron images and elemental analysis are combined to study the decorative enamelled surface. The compositions of the layers within the enamel, that of the counter enamel and the polychrome decoration on the surface are determined and identified. Fluorine and elevated amounts of calcium were detected, indicating that fluorite was likely used as a raw material. The presence of this mineral, which is typical of Chinese cloisonne, confirms that these objects share both aesthetic and technological relationships. Show less
Lead-barium glass appeared during the late Warring States period in China (457 -221 BCE) and was considered as a Chinese invention due to the unique presence of high barium. There is no indication... Show moreLead-barium glass appeared during the late Warring States period in China (457 -221 BCE) and was considered as a Chinese invention due to the unique presence of high barium. There is no indication as to how it was made. A set of twenty-four different combinations of possible raw materials were melted to test and systematically evaluate the possible recipes for lead-barium glass. Specifically, the function and source of sodium in lead -barium glass were explored. The results show that sodium source is crucial for lead-barium glass forming in this particular system. This paper explores an alternative formulation since sodium flux is not reported in historical Chinese sources, in which the Na2O is provided by including soda-lime glass in the mixture. This particular formulation provides a potential explanation for the source of the sodium in lead-barium glass. Show less
Dillis, S.; Van Ham-Meert, A.; Leeming, P.; Shortland, A.; Gobejishvili, G.; Abramishvili, M.; Degryse, P. 2019
Sb was frequently used as a raw material, both in ancient glass-making (as an opacifier and decolouriser) and metallurgy (either as an alloying element or as a pure metal). Despite this ubiquity,... Show moreSb was frequently used as a raw material, both in ancient glass-making (as an opacifier and decolouriser) and metallurgy (either as an alloying element or as a pure metal). Despite this ubiquity, antimony production has only occasionally been studied and questions concerning its provenance are still not satisfactorily answered. This study evaluates the suitability of Sb isotope analysis for provenance determination purposes, as experiments under lab conditions have revealed fractionation occurring during redox processes in oxidising stibnites and in making opacified glasses. The results of this paper help to evaluate the possible influence of the pyrotechnological processes on the antimony isotope composition of glass artefacts. This paper focuses on the Caucasus as case study by applying mineralogical, geochemical and isotopic analysis to Georgian ores (mainly from the Racha-Lechkumi district) and Late Bronze Age (LBA; 15th-10th century BCE) metallic Sb objects found at the sites of Brili and Chalpiragorebi.[GRAPHICS]. Show less
Van Ham-Meert, A.; Dillis, S.; Blomme, A.; Cahill, N.; Claeys, P.; Elsen, J.; ... ; Degryse, P. 2019
In large parts of the Mediterranean recipes for the earliest man-made glass changed from melting mixtures of crushed quartz pebbles and halophytic plant ashes in the Late Bronze Age to the use of... Show moreIn large parts of the Mediterranean recipes for the earliest man-made glass changed from melting mixtures of crushed quartz pebbles and halophytic plant ashes in the Late Bronze Age to the use of quartz sands and mineral soda during the Early Iron Age. Not much is known about this transition and the experimental materials which would inevitably have been connected to such technological change. In this paper we present a unique snapshot of developments in glass technology in Anatolia during the Middle Iron Age, when glass is still a relatively rare commodity. The present work focusses on black glass beads decorated with yellow trails from eighth to seventh century BCE Sardis, glass beads that are very rare for this period, and on this site. A full elemental analysis of the beads was made, and Sr, Pb and B isotope ratios were determined. This study reveals the use of a combination of a previously unknown source of silica and of mineral soda, giving rise to elevated (granite-like) Sr isotope signatures, as well as high alumina and B concentrations. The yellow trails of glass on the beads consist of lead-tin yellow type II, lead stannate, showing the earliest occurrence of this type of opacifier/colourant so far, predating any other findings by at least four centuries. The production of these glass beads may be local to Sardis and experimental in nature. It is therefore suggested that Sardis may have played its role in the technological development of the glass craft during the Iron Age. Show less
