Countermark

https://rpc.ashmus.ox.ac.uk/countermark/928 
GIC 813
denominational mark Ϛ
circular 
6.5 mm 
Sometimes on reverse 

Coins with this countermark

Number Image TypeNumber CoinNumber VolumeNumber
RPC X, — (number not assigned), type ID 61345 Show 1637 6 10
RPC X, — (number not assigned), type ID 61345 Show 1637 5 10
RPC X, — (number not assigned), type ID 61345 Show 1637 1 10
RPC X, — (number not assigned), type ID 61345 Show 1637 2 10
RPC X, — (number not assigned), type ID 61346 Show 1636 1 10
RPC X, — (number not assigned), type ID 61347 Show 1665 4 10
RPC X, — (number not assigned), type ID 61348 Show 1666 6 10
RPC X, — (number not assigned), type ID 61348 Show 1666 4 10
RPC X, — (number not assigned), type ID 61348 Show 1666 3 10
RPC X, — (number not assigned), type ID 61350 Show 1664 1 10
RPC X, — (number not assigned), type ID 61352 Show 1663 11 10
RPC X, — (number not assigned), type ID 61352 Show 1663 3 10
RPC X, — (number not assigned), type ID 61357 Show 1672 5 10
RPC X, — (number not assigned), type ID 61357 Show 1672 9 10
RPC X, — (number not assigned), type ID 61357 Show 1672 10 10
RPC X, — (number not assigned), type ID 82877 Show 1674 2 10
RPC X, — (number not assigned), type ID 61358 Show 1680 3 10
RPC X, — (number not assigned), type ID 61358 Show 1680 4 10
RPC X, — (number not assigned), type ID 61358 Show 1680 2 10
RPC X, — (number not assigned), type ID 61358 Show 1680 7 10
RPC X, — (number not assigned), type ID 61358 Show 1680 13 10
RPC X, — (number not assigned), type ID 61362 Show 1678 5 10
RPC X, — (number not assigned), type ID 61363 Show 1681 1 10
RPC X, — (number not assigned), type ID 61363 Show 1681 4 10
RPC X, — (number not assigned), type ID 61519 Show 1721 12 10
RPC X, — (number not assigned), type ID 61345 Show 1637 10 10
RPC X, — (number not assigned), type ID 61345 Show 1637 14 10
RPC VI, 5352 (temporary) Show 4967 2 6