Countermark

https://rpc.ashmus.ox.ac.uk/countermark/902 
GIC 773
denominational mark Γ
incuse 
applied to worn coins with an additional countermark (GIC 34, 35 or 36) 

Coins with this countermark

Number Image TypeNumber CoinNumber VolumeNumber
RPC VI, 4669 (temporary) Show 3754 8 6