The technological development of stonepaste ceramics from the Islamic Middle East
Abstract The microstructures and chemical compositions of stonepaste bodies from the Islamic Middle East, typically produced from a mixture of ten parts crushed quartz, one part crushed glass and one part white clay, are investigated using analytical scanning electron microscopy. For comparison, replicate stonepaste bodies are produced in the laboratory at firing temperatures in the range 900–1200 °C, and are similarly examined. The stonepaste bodies are divided into four primary microstructural groups that reflect the increasing reaction during firing of the glass fragments with the clay and quartz particles. The observed microstructures are then used to assess the geographical and chronological variations in the production technology of stonepaste ceramics from Egypt, Syria, Iran, Uzbekistan and Turkey, spanning the period from 11th to 17th centuries AD.
IZNIK POTTERY: AN INVESTIGATION OF THE METHODS OF PRODUCTION
range of vibrant underglaze colours. Initially produced as a substitute for imported Chinese blue-and-white porcelain, the generally accepted sequence for the de- velopment of Iznik pottery starts in about 1480 with ‘Abraham of Kutahya’ ware and continues through ‘Golden Horn’ and ‘Damascus’ wares to bole red ware, the production of which began in the 1550s and continued to the seventeenth century (Rogers and Ward 1988. 186-8). The decoration of the ‘Abraham of Kutahya’ and ‘Golden Horn’ wares is predominantly blue whereas that of the ‘Damascus‘ and bole red wares is polychrome. The extent to which these different types were made simultaneously has not yet been fully resolved. The ‘Abraham of Kutahya’ and ‘Golden Horn’ wares appear to have been produced at both Kutahya and Iznik. In contrast, the ‘Damascus’ and bole red wares appear to have been made exclusively at Iznik. In the Ottoman sources ‘Iznik pottery’ is used more as a trade name than a provenance. Therefore, it must be emphasised that in using the term, as well as the terms ‘Abraham
FAIENCE: AN INVESTIGATION OF THE MICROSTRUCTURES ASSOCIATED WITH THE DIFFERENT METHODS OF GLAZING
The microstructures of faience, produced in the laboratory by the direct application of the glazing mixture (both in the raw state and in the form of prefired and ground frit) and by the efflorescence and cementation glazing methods, have been studied in polished sections in the scanning electron microscope (SEM). The microstructures observed were defined in terms of (1) thickness of the surface glaze layer, (2) thickness of the glaze-core interaction layer, (3) nature of the boundary between the interaction layer and the core and (4) extent of any interstitial glass phase within the quartz core. These parameters provide the basis for distinguishing between faience made by the three principal methods of glazing used in antiquity. Hence the method used to glaze an ancient faience object can be inferred from its microstructure as observed in polished section in the SEM.