Sent for ID: Mark replied:
This one is pretty simple, despite the near total lack of legend, it’s clearly a posthumous CONSECRATIO issue billon antoninianus of Claudius Gothicus (died 270)
The rectilinear pattern on the reverse – an altar enclosure with paneled doors – was very easy for local engravers to copy, so this is one of the most frequently encountered pieces in the field of contemporary copies – second only to the Tetricus I PAX AVG copies.
Gothicus official antoniniani – at least his later ones and posthumous issues – are among the most tawdry, slipshod productions to emerge from the huge minting establishment at Rome. One of the first things Aurelian, Gothicus’ first serious successor, had to deal with was to put down what had become an armed rebellion by the (literally) thousands of workers and slaves in the Roman mint community – they had pretty much broken off from the Empire and were pursuing their own path as an independent organization given the power vacuum of the late 260’s. Mark