Oldest Known Stone Mould Discovered in Roman Hispania, Shedding Light on Coin Production

Excavations at the ancient settlement of Obulco in Porcuna, Spain, have unearthed the oldest evidence of coin production in Roman Hispania. This important discovery by archaeologists from the University of Jaén was announced by ‘La Brújula Verde’ and opens a unique window on economic practices in antiquity.

Obulco was a vibrant city, both commercially and culturally, rising in the heart of the Iberian Peninsula in the 2nd century BC. Its mint produced coins with a blend of local and Roman influences. However, mint remains from that period are extremely rare, leaving the question of where and how coin production took place unanswered.

This is where the found stone mould comes into play. This mould, measuring approximately 11×13.7×5.4 cm, is half of a two-part mould used in coin minting. The circular marks and heat marks on the mould confirm that it was used for making coins. The fact that it was made of local stones indicates that local resources were used for industrial purposes at that time.

When the metal traces on the mould were analysed, the same copper-lead alloy as the coins minted in Obulco was found. This indicates that the mould is related to the production of bronze aces dated between 189-165 BC. Obulco was one of the most active mints in southern Hispania at the time, and its coins reflect the city’s integration into the Roman economic system.

The discovery of the mould in a suburban area close to the city walls provides new clues to the location of the mint. Similar findings at Carteia suggest that mints may have been located on the outskirts of the city, under the control of local rulers or the military.

This discovery not only sheds light on the technical details of coin production, but also reveals the socioeconomic impact of Rome in Hispania. The coins minted at Obulco show that local and Roman governments were intertwined. Increased coin production is also considered as a reflection of Rome’s economic dominance in the region.

This mould is an important step in tracing ancient mints and helps us understand the economic and social dynamics in Roman Hispania. It shows how coins bridged the local and Roman worlds.

María Isabel Moreno-Padilla, Mario Gutiérrez-Rodríguez, et al., Dealing with the archaeological invisibility of the Iberian mints: A technological and contextual analysis of the first stone mould for blank coin production found in Hispania. Journal of Archaeological Science: Reports, Volume 63. Doi.org/10.1016/j.jasrep.2025.105083

Cover Image Credit: Detailed images of the stone mould used for blank coin production. It corresponds to the flat valve of a bivalve mould. Credit: M.I. Moreno-Padilla et al.