Countermark

https://rpc.ashmus.ox.ac.uk/countermark/640 
GIC 513
Α•Κ
rectangular 
5.5 x 2.5 mm 
meaning of the letters is uncertain. Sometimes on reverse. Unlike GIC 334 (eagle) 513 is not found on the coins od Severus Alexander and was therefore the earlier of the two. 

Coins with this countermark

Number Image TypeNumber CoinNumber VolumeNumber
RPC VI, 6115 (temporary) Show 5845 2 6
RPC VI, 6117 (temporary) Show 5854 5 6
RPC VI, 6127 (temporary) Show 5852 2 6
RPC VI, 6123 (temporary) Show 5850 1 6
RPC VI, 6126 (temporary) Show 5860 17 6
RPC VI, 6111 (temporary) Show 5843 4 6
RPC VI, 6116 (temporary) Show 5851 2 6
RPC VI, 6117 (temporary) Show 5854 17 6
RPC VI, 6113 (temporary) Show 5857 1 6
RPC VI, 6121 (temporary) Show 5846 2 6
RPC VI, 6117 (temporary) Show 5854 4 6
RPC VI, 6125 (temporary) Show 5856 1 6
RPC VI, 6113 (temporary) Show 5857 3 6
RPC VI, 6112 (temporary) Show 5844 1 6
RPC VI, 6117 (temporary) Show 5854 7 6
RPC VI, 6117 (temporary) Show 5854 6 6
RPC VI, 6114 (temporary) Show 5861 2 6
RPC VI, 6126 (temporary) Show 5860 9 6
RPC VI, 6117 (temporary) Show 5854 18 6
RPC VI, 6117 (temporary) Show 5854 20 6
RPC VI, 6121 (temporary) Show 5846 4 6
RPC V.3, — (number not assigned), type ID 80677 Show 141 1 5.3
RPC VI, 6126 (temporary) Show 5860 19 6
RPC VI, 6116 (temporary) Show 5851 5 6
RPC VI, 6117 (temporary) Show 5854 21 6
RPC VI, 6118 (temporary) Show 5859 2 6
RPC VI, 6121 (temporary) Show 5846 6 6
RPC V.3, — (number not assigned), type ID 80860 Show 179 3 5.3
RPC V.3, — (number not assigned), type ID 80821 Show 171 1 5.3
RPC V.3, — (number not assigned), type ID 81053 Show 175 2 5.3
RPC V.3, — (number not assigned), type ID 81236 Show 176 1 5.3
RPC V.3, — (number not assigned), type ID 81053 Show 175 1 5.3
RPC V.3, — (number not assigned), type ID 80720 Show 69 2 5.3
RPC V.3, — (number not assigned), type ID 80701 Show 77 1 5.3
RPC V.3, — (number not assigned), type ID 81174 Show 72 1 5.3
RPC V.3, — (number not assigned), type ID 80700 Show 79 1 5.3
RPC V.3, — (number not assigned), type ID 81000 Show 81 1 5.3
RPC V.3, — (number not assigned), type ID 80916 Show 82 2 5.3
RPC V.3, — (number not assigned), type ID 80914 Show 84 1 5.3
RPC V.3, — (number not assigned), type ID 81237 Show 178 1 5.3
RPC V.3, — (number not assigned), type ID 80675 Show 138 2 5.3
RPC V.3, — (number not assigned), type ID 80675 Show 138 8 5.3
RPC V.3, — (number not assigned), type ID 80712 Show 139 1 5.3
RPC V.3, — (number not assigned), type ID 80696 Show 150 2 5.3
RPC V.3, — (number not assigned), type ID 83833 Show 83 1 5.3
RPC V.3, — (number not assigned), type ID 80675 Show 138 6 5.3
RPC V.3, — (number not assigned), type ID 87002 Show 78 1 5.3
RPC VI, 6111 (temporary) Show 5843 6 6
RPC VI, 6117 (temporary) Show 5854 28 6
RPC VI, 6115 (temporary) Show 5845 3 6
RPC V.3, — (number not assigned), type ID 86045 Show 142 2 5.3
RPC V.3, — (number not assigned), type ID 80699 Show 148 6 5.3
RPC V.3, — (number not assigned), type ID 91431 Show 153 1 5.3
RPC V.3, — (number not assigned), type ID 81174 Show 72 2 5.3
RPC VI, 6126 (temporary) Show 5860 23 6