The blues of Romuliana

A unique set of cobalt-blue glass fragments, including mosaic tesserae and architectural decoration remnants, was uncovered at the late Roman imperial residence Gamzigrad-Romuliana (Serbia). Chemical analysis confirmed that the blue pigment in all samples originated from cobalt, with notable antimony levels suggesting intentional opacification. The findings, dated to the 4th century, reveal a likely Syro-Palestinian provenance for most glass, with one sample possibly linked to Egyptian production. The discovery of furnace debris and window pane fragments within the site hints at local glassworking activities. Additionally, correlations in oxide concentrations imply standardized late Roman production practices, offering new insights into the craftsmanship and trade networks of the period.

Jovanovic, S., Cholakova, A., Pop-Lazic, S., Freestone, I., & Zivkovic, M. (2021). The blues of Romuliana. Starinar, (71), 207–230. https://doi.org/10.2298/sta2171207j