Changes in the body,glaze and enamel compositions of early Meissen porcelain, 1723–c.1740

The evolution of early Meissen body, glaze and colorant compositions is examined using X-ray fluorescence spectroscopy (XRF) measurements on three artefacts that can be accurately dated to the period 1723–c.1740. The results are interpreted based on recipes recorded in the earliest documents of the Meissen archives. The pure Aue kaolinite contains low levels of Ti and can be distinguished from secondary clays, for example, clay from Colditz. The excess Ti in the glaze versus the body reported earlier and confirmed by the present authors is explained by the exclusive use of Colditz clay for the glaze, as described in the recipes before 1730, providing a terminus ante quem for Meissen porcelain exhibiting this particular asymmetry. After 1730, the presence of elevated Ti in the body could serve as a marker for the experimental admixture of clays to Aue kaolinite to alter its properties. Based on the detection of As, Ba and Bi, it is suggested that smalt from Erzgebirge was the colorant for blue enamels until at least 1725.     

On the blue and green pigments of post-Byzantine Greek icons

In the framework of a large-scale investigation of post-1453 ce icons, the blue and green pigments on more than 50 works were investigated. Studied works date from the mid-15th to the mid-19th centuries and originate from various modern-day Greek regions. Results indicate the use of both natural and artificial pigments; among the latter, the very poorly documented in Greek icons artificial Cu-based blue is included. A shift as regards the use of specific pigments is reported and local trends are compared with the contemporary Western European ones. Relevant terms found in the renowned Hermeneia craftsman's handbook are also discussed in an attempt to restore pertinent misconceptions.     

Smalt production in the Ore Mountains: Characterization of samples related to the production of blue pigment in Bohemia

The study deals with the chemical composition of samples related to the production of a blue pigment/smalt. The samples examined come from the regions of Soví huť and Horní Blatná (north-west Bohemia) dating to the 16th and 17th centuries. These locations are often mentioned in relation to the discoverer of smalt production technology: Christopher Schürer. The aim of the study is to evaluate the chemical composition of samples from both localities as well as with respect to the ores occurring in the given regions. The samples can be divided into two basic groups. The first clearly represents smalt (potassium glass coloured with cobalt), while the second apparently constitutes the samples of the so-called ‘speiss’ (an aluminosilicate mass with metallic compounds). The analysis of the smalt confirmed the representation of minor elements bismuth and nickel (always) and uranium and molybdenum (rarely), which are found in Co ores from the Ore Mountains. The paper is the first to present the composition of actual blue pigment finds originating directly from the production sites, while the available literature has so far only reported the results of analyses of the pigments already used when referring to the Ore Mountains.