Artificial or natural origin of hematite-based red pigments in archaeological contexts: the case of Riparo Dalmeri (Trento, Italy)

This study concerns those crystallographic and microstructural features that can provide indications on the actual origin of red pigments based on hematite (Fe2O3). The main features of natural and artificial hematite are recalled and used to discuss the results obtained from the characterization of red-ochre samples coming from the Palaeolithic site of Riparo Dalmeri, a rock-shelter located in northeastern Italy, dated to 13 000 cal. BP, and notorious for the presence, among the other finds, of red-painted calcareous stones. Painting and the treatment of leather and hides obtained from the intensive hunting activity were the main uses of the hematite-based red-ochres at Riparo Dalmeri. It turns out that hematite was mostly obtained from the thermal treatment of goethite, which, unlike hematite, was and still is widely available in the neighbourhood of the site.