Countermark

https://rpc.ashmus.ox.ac.uk/countermark/572 
GIC 452
star of six rays
circular 
4 mm 
one on reverse. Possibly the same cmk as GIC 456? 

Coins with this countermark

Number Image TypeNumber CoinNumber VolumeNumber
RPC II, 1619 Show 1619 7 2
RPC I, 5005 Show 5005 10 1