The reverse of this coin has a small circular punch in the right field. It was struck hard enough that it made a raised area on the obverse to the left of the chin. I have seen similar punches on Indian coinage; but typically much earlier than this coin was struck. Maybe it has no significance at all. It also has patina and a bit of green indicating it was not done recently. Constantine II A.D. 324- 325 AE nummus 17x19mm 2.7g CONSTANTINVS IVN NOB C; Laureate, draped and cuirassed bust left. PROVIDENTIAE CAESS; campgate, two turrets, no doors, ✶ above. In ex. STR RIC VII Trier 455