Countermark

https://rpc.ashmus.ox.ac.uk/countermark/1014 
GIC 457 .1
star, or rosette, or ·Ι· (?=Φ)
On reverse 

Coins with this countermark

Number Image TypeNumber CoinNumber VolumeNumber
RPC I, 4951 Show 4951 2 1
RPC I, 4951 Show 4951 13 1