MATERIAL CHARACTERIZATION OF CERAMIC TILE MOSAIC FROM TWO 17TH‐CENTURY ISLAMIC MONUMENTS IN NORTHERN INDIA

Coloured tiles from two northern Indian monuments were analysed for their body and glaze composition. The results suggest that three different groups of tiles were used, all comprising a stonepaste body with alkali glaze. One group has strong similarities to a major Indian glass group, known as high alumina mineral natron glass, while the other two are similar to Western and Central Asian plant ash glazes, although with much lower lime content. The colorants conform with those usually employed in pre‐modern glazes, with lead‐tin yellow Type I and Type II for opaque yellow, copper blue‐turquoise, cobalt blue, manganese purple, and green through mixing of lead‐tin yellow and copper blue.     

ANCIENT EXPLOITATION AND USE OF COBALT ALUMS FROM THE WESTERN OASES OF EGYPT*

Cobalt alums from the Western Oases of Egypt were used in the second millennium bc as a colorant to produce dark blue glasses and glazes. A collection of these alums was gathered together and analysed by a series of techniques to accurately characterize them. They were then used alongside artificial analogues in experimental work aiming to determine the process that was used to convert the raw alum into a suitable pigment that might be used in a glass. Finally, the broader picture of the use of these alums is considered together with the implications for the trade in these materials across the Near East and into Europe.     

THE TECHNOLOGY OF GLAZED ISLAMIC CERAMICS USING DATA COLLECTED BY THE LATE ALEXANDER KACZMARCZYK

During the 1980s, the late Alexander Kaczmarczyk undertook the analysis of some 1200 glazed Islamic ceramics from Egypt, Iran, Iraq and Syria spanning the period from the eighth to the 14th centuries ad , using a combination of XRF for the glazes, and AAS or PIXE for the bodies. The aim of the present paper is, first, to bring to the attention of researchers into Islamic ceramics the fact that these analytical data are available on the Research Laboratory for Archaeology and the History of Art website, and also that some 400 of the analysed sherds are held in the Research Laboratory. Second, the paper provides a preliminary interpretation of the analytical data in terms of the choice of glaze type (i.e., alkali–lime, lead–alkali and high‐lead), tin‐opacification, body type (i.e., quartz or stonepaste, calcareous clay, and non‐calcareous clay), and colorants.     

Coloured Prints of the 16th Century: Non‐Destructive Analyses on Coloured Engravings from Albrecht DÜrer and Contemporary Artists

Qualitative investigations of pigments and dyes using micro X‐ray fluorescence spectrometry (micro‐XRF) and visible spectrophotometry (VIS) are suitable non‐destructive methods for the characterization of different colorants in art objects. In this study, several rare coloured engravings from the work of Albrecht Dürer—and, in addition, from the work of Cornelis Cort, Servatius Raeven and Johannes Sadeler—were investigated. The analyses result in specific palettes of colours that were used by different artists or in different workshops for the coloration of engraved images. Starting from these different palettes, it is possible to distinguish coeval colorations that were added in the 16th century from those that were carried out at a later date (e.g., the 19th century).     

The use and origin of antimonate colorants in early Egyptian glass*

The origin of the colorants in Egyptian glass of the second millennium BC has been the subject of much research and debate. Several colorants including lead antimonate yellow and calcium antimonate white appear in the archaeological record apparently concurrently with the introduction of glass, and it is possible that their origins are in some way linked. This paper examines the use of the antimonate colorants and uses analytical and experimental techniques to deduce possible technologies of production. Trace element data derived from a pilot study by LA‐ICPMS gives additional indications of a possible source in the Caucasus for the antimony of these glasses.