Countermark

https://rpc.ashmus.ox.ac.uk/countermark/46 
GIC 810
denominational mark Ϛ
square 
5 x 5 mm 
Pionia (Mysia)
Denominational countermarks in rectangular punches are found of coins of Mysia, Troas and Aeolis, and were possibly applied in one city in that region 
List of countermarks View on a map

Coins with this countermark

Number Image TypeNumber CoinNumber VolumeNumber
RPC VII.1, 147 Show 147 4 7.1