X-ray powder diffraction investigations of Ruthenian-Byzantine frescoes from the royal Wawel Cathedral (Poland)

Abstract

Laboratory X-ray powder diffraction was applied to investigate the pigments used by medieval artists in Ruthenian-Byzantine frescoes in the royal Wawel Cathedral in Krakow (Poland). It was found that red fragments contained cinnabar (PDF 06-0256), yellow contained goethite (PDF 29-0713), and blue pieces contained azurite (PDF 02-0153). The green pigment, quite difficult to identify, was finally established as green earths—pigments commonly used in Byzantine wall paintings. Calcite (PDF 24-0027) was detected in all the samples. Small amounts of quartz (PDF 46-1045) in the plaster samples were also detected. The absence or presence of only minute amounts of quartz is a characteristic feature of the Ruthenian-Byzantine frescoes. Malachite was not detected in the green parts of the frescoes, in contrast to earlier investigations of wall paintings in Poland. Experimental details and the results obtained in this study are described and discussed.