Analytical studies on medieval lead ingots from Wrocław and Kraków (Poland): a step towards understanding bulk trade of lead from Kraków and Silesia Upland Pb–Zn deposits

Abstract

Origins of medieval lead artefacts are hard to establish due to re-smelting and mixing. One can obtain conclusive evidence from ingots that served for bulk trade and originated directly from the mines. This paper aims to analyse the thirteenth century lead ingot from Wrocław (Poland). To establish its origins we analysed its structure and chemical composition. We used archaeometric methods: light and electron microscopic observations, X-ray fluorescence spectrometry, X-ray diffraction, infrared spectroscopy, inductively coupled plasma-optical emission spectrometry and Pb isotopic analysis. We compared our measurements with measurements of analogical ingot found on Kraków Market Square and a database of lead ores from Europe and the Middle East. The research indicated that both ingots originated from -Kraków and Silesia Upland Pb–Zn ore deposits (Poland), intensively mined from the twelfth century. The results complement the view of trade routes established based on written records and add valuable data for future comparative studies.