Ochres as earth pigments in Hellenistic and Roman polychromy: State of the art and future directions on material origins and trade

Ochres are naturally occurring materials that are abundant in various geological environments and geographic regions and that have been used for a range of different purposes throughout history. Their wide use as pigments in ancient art is well-documented and, due to their abundancy, it is often presumed that ochres were extracted from locally available sources. However, ancient literary sources underline a preference for ochres from specific regions and provenance is viewed as a signifier for different properties, uses, and values. Despite the evident importance of ochre provenance for Hellenistic and Roman art, research on the topic remains scarce. This review paper aims to bridge archaeological and literary evidence with science-based methodological approaches that contribute to ochre provenance research. Firstly, an overview of ancient texts discussing terminology and the significance of ochre provenance and trade during the Hellenistic and Roman period is presented. Secondly, archaeological science-based approaches to ochre provenance research are reviewed, sketching out the contribution of interdisciplinary research to ancient ochre research, with a focus on evaluating possible raw material sources. Finally, this paper explores future directions that could contribute to the contextualisation of science-based approaches of ochre-provenance research within the framework of Classical Mediterranean archaeology, a period for which textual and historical evidence complement archaeological finds. • Ochre provenance is a signifier of their socio-economic value during the Hellenistic and Roman periods. • Archaeological and literary evidence contribute to science-based methodologies for ochre provenance research. • Research on Graeco-Roman polychromy would benefit from archaeometric approaches applied on prehistoric contexts. • Ochre provenance research would benefit from the use of certified reference materials and a wider range of source areas. • The development of ochre-specific databases would contribute to provenance research.