A PRELIMINARY INVESTIGATION OF BLACK, BROWN AND RED COLOURED POTSHERDS FROM ANCIENT UPPER MACEDONIA, NORTHERN GREECE

Abstract

Black, red and brown coloured surfaces of several ancient potsherds from an archaeological site of northern Greece, dated from the prehistoric (16th c. BC) to the Hellenistic (3rd c. BC) era were ana‐lysed by Raman microspectroscopy, non‐destructive X‐Ray Diffraction (XRD), Environmental Scan‐ning Electron Microscopy coupled to Energy Dispersive system (ESEM‐EDX) and Thermogravim‐etry (TG). Black colour comprises of amorphous carbonaceous material and iron oxides (hematite and/or magnetite), red colour is due to hematite (the raw material being iron oxides and hydroxides either from an ochre deposit or an iron‐rich clay deposit) and brown from a mixture of hematite and calcite. The decoration seems to have been applied before firing, and the colours were obtained of mixtures of specific proportions of the main constituents and by controlling the kiln atmosphere (combined reducing and oxidizing). The possibility of post‐firing decoration on the prehistoric sample is also discussed.