Cinnabar for Roman Ephesus: Material quality, processing and provenance

Ephesus was an important harbor city that flourished during the Roman period and ancient texts mention Almadén in Spain and the Cilbian fields of Ephesus as important cinnabar sources in antiquity. This work investigates whether imported cinnabar was used and whether this could be related to changes in painting activities over time. Microscopic analysis indicates a consistent preparation of cinnabar, hinting at a uniform source material quality or processing technique. However, the use of cinnabar varies among the architectural structures studied, indicating a plurality of painting techniques. A few of the analyzed cinnabar samples overlap with Turkish- and Balkan reference Pb isotope ratios; three samples from tabernas, however, deviate from this. The Hg isotope ratios reveal that cinnabar from carbonate-hosted deposits was likely used, and that processing of cinnabar included heating as suggested by ancient texts. Most notably, a correlation exists between the geochemical data and the painting technique – shifts in sourcing and cinnabar usage are potentially assignable to building chronology and/or usage. Through the lens of material provenance and processing, Ephesian cinnabar brings the organization of pigment trade into focus.