Black »marble« in the Polish architecture - characteristics and possibility of its provenance determination: the case of the Dębnik limestone

Abstract

Black limestone, also known as black »marble«, was widely used in the Polish small-scale architecture and art of the 17$^{th}$ and 18$^{th}$ centuries. Besides the Devonian limestone from Dębnik near Krakow, also popular were the Netherlandish (Wallonian), Devonian to Carboniferous limestones from the Meuse River and Schelde River valleys. This paper deals with the possibility of identifying the rocks imported to Poland. Macroscopic similarities between the Netherlandish rocks and some Dębnik limestones have been highlighted for the oldest Carmelite quarry in Dębnik, exploiting the best stones. The analyses include: optical microscopy, scanning electron microscopy with EDS, X-ray diffraction, X-ray fluorescence and isotope ratio mass spectrometry ($^{13}$C and $^{18}$O stable isotopes). Carboniferous limestones from Netherlands can be identified within and distinguished from the Dębnik limestone in the macroscopic observations. Differences, depending on the varieties, are associated primarily with the presence of white calcite fragments of fossils, calcite veins intersecting the rock in all directions or hardness of the limestones. Deeply black Devonian limestones from Wallonia and Dębnik without macrofossils and calcite veins differ in microscopic observations considering their texture, type of microfossils and inventory of non-carbonate components. The characteristic graying and whitening of the black limestones has also been discussed as a possible feature of rock provenance.