Countermark

https://rpc.ashmus.ox.ac.uk/countermark/623 
GIC 499
?, 'crescent' or 'lunate sigma'
incuse 
5 mm long 
 

Coins with this countermark

Number Image TypeNumber CoinNumber VolumeNumber
RPC VI, 6855 (temporary) Show 6402 2 6
RPC VI, 6857 (temporary) Show 6404 1 6
RPC VI, 6858 (temporary) Show 6405 1 6