Petrographic and XRD Analysis of the Ceramic Body of Late Medieval Besztercebánya/banská Bystrica-Type Stove Tiles

A unique collection of high-quality late Medieval (15th-16th century) glazed stove tiles from the northern part of the Carpathian Basin is of great interest to archaeologists and art historians. Tiles of identical style, motifs and sizes were found in twenty-eight different localities. It is yet to be determined whether these products were made in a single workshop, perhaps in Besztercebanya/Banska Bystrica (in present-day Slovakia) or in multiple workshops in the region. In the present study, the ceramic body of ninety-four tile fragments from six sites (Besztercebanya/Banska Bystrica, Fulek/Filakovo and Csabrag/Cabrad in Slovakia; Salgo, Eger and Szecseny in Hungary) was investigated using polarizing microscopy and X-ray diffraction analysis to determine the raw materials and production techniques used. Based on the petrographic characteristics and phase composition the tiles can be classified into four main groups. Samples from the Hungarian sites and Fulek/Filakovo - apart from one tile from Eger - are comprised of similar raw materials. Use of intentionally tempered clay is probable in the largest subgroup, in which large angular rock fragments are dominant. By contrast, stove tiles from Besztercebanya/Banska Bystrica contain variable rock fragments (granitoid, quartzite, limestone). Tiles from Csabrag/Cabrad form an independent group due to the presence of large amount of volcanic rock fragments with strong hydrothermal alterations. Based on the preliminary study of the ceramic body the tiles analysed were likely made in several workshops. Nevertheless, the use of identical motifs indicates a possible connection between the workshops.