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

Abstract

Between the 2nd and 1st centuries BCE, a significant number of mints emerged in the Iberian Peninsula, producing coins either continuously or on an ad hoc basis. Despite the large number of workshops, we have little material evidence of their locations beyond the coins themselves. This leaves many gaps regarding where the mints were located in the topography of ancient towns, the chaîne opératoire, or the social organisation around the workshops. In this study, we present a stone mould for blank coin production found in excavations carried out in the Iberian oppidum of Obulco, modern-day Porcuna (Jaén, Spain). Petrographic analysis has documented the local origin of the raw material used. Use-wear analysis has shown technical marks associated with its use as a coin mould. µ-XRF analysis of the metallic imprints on its surface has confirmed that a binary Cu-Pb alloy was used. This observation fits previous elemental characterisation studies of Obulco coins. The metric analysis of the metallic impressions leads us to propose the production of bronze asses dated to the 2nd century BCE, more specifically between 189/165–146 BCE. Our study has a dual uniqueness: the blank coin mould presented in this paper is the only one found so far in the Iberian Peninsula, and it is one of the few coin production tools documented in archaeological context. This has implications for the understanding of coinage production processes and locative decisions of mints in ancient Hispania, which are traditionally defined by their archaeological invisibility.