Countermark

https://rpc.ashmus.ox.ac.uk/countermark/1373 
GIC
star (or rosette) with six rays
circular 
4–4.5 mm 
This cmk is similar to GIC 434, It is separated due to the western Greek origin of the coins from Zacynthus, and a presumed Pontic origin for the coins attributed to Augustus of "Coinage with Q" 

Coins with this countermark

Number Image TypeNumber CoinNumber VolumeNumber
RPC I, 5409 Show 5409 76 1
RPC I, 5410 Show 5410 15 1
RPC I, 5410 Show 5410 17 1
RPC I, 5410 Show 5410 19 1
RPC I, 5410 Show 5410 33 1
RPC I, 5410 Show 5410 34 1
RPC I, 5410 Show 5410 35 1