Countermark

https://rpc.ashmus.ox.ac.uk/countermark/173 
GIC 52
radiate head of bust of emperor r.; on obverse (one on reverse)
circular 
5.5 mm 
Alabanda (Caria)
the placing of one stamp on the reverse was probably due to the earlier countermark (GIC 39) on the obverse 
List of countermarks View on a map

Coins with this countermark

Number Image TypeNumber CoinNumber VolumeNumber