20 Decimae Countermark

Populonia's bronze coinage is unusual among Etruscan issues in carrying countermarks applied well after original minting — the "XX" punch indicating a revaluation or reauthorization for continued circulation rather than a fresh strike. The city's monetary output had largely ceased by the late third century BC, meaning these marked pieces were doing work in a system that had already absorbed Populonia politically into the Roman sphere.

The Vecchi-IV classification places this among a small, well-documented group, but findspot evidence remains thin.