Countermark

https://rpc.ashmus.ox.ac.uk/countermark/906 
GIC 778
denominational mark Γ
incuse 
6 mm (vertical) x 4 mm (lateral) 
Ariassus (Pisidia)
The cmks were probably contemporary with the coins of Gallienus and Salonina which had a Γ in the reverse field, as the I of GIC 835 
List of countermarks View on a map

Coins with this countermark

Number Image TypeNumber CoinNumber VolumeNumber
RPC VI, 5995 (temporary) Show 5636 3 6
RPC VI, 5992 (temporary) Show 5632 1 6
RPC VI, 10982 (temporary) Show 5633 1 6
RPC VI, 5995 (temporary) Show 5636 2 6