This is an authentic ancient Roman silver coin from the period of Postumus, ruling the Roman splinter state of the Gallic Empire from 260 to 269 AD. The coin is uncleaned and ungraded, but its historical value is certain. The denomination of the coin is Antoninianus, and it is a piece of history from the Roman era. Its provenance is not available. This coin is a rare find for collectors and enthusiasts of ancient coins.