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 5910 2 6
RPC VI, 6117 (temporary) Show 5919 5 6
RPC VI, 6127 (temporary) Show 5917 3 6
RPC VI, 6123 (temporary) Show 5915 1 6
RPC VI, 6126 (temporary) Show 5925 17 6
RPC VI, 6111 (temporary) Show 5908 4 6
RPC VI, 6116 (temporary) Show 5916 2 6
RPC VI, 6117 (temporary) Show 5919 17 6
RPC VI, 6113 (temporary) Show 5922 1 6
RPC VI, 6121 (temporary) Show 5911 2 6
RPC VI, 6117 (temporary) Show 5919 4 6
RPC VI, 6125 (temporary) Show 5921 1 6
RPC VI, 6113 (temporary) Show 5922 3 6
RPC VI, 6112 (temporary) Show 5909 1 6
RPC VI, 6117 (temporary) Show 5919 7 6
RPC VI, 6117 (temporary) Show 5919 6 6
RPC VI, 6114 (temporary) Show 5926 2 6
RPC VI, 6126 (temporary) Show 5925 9 6
RPC VI, 6117 (temporary) Show 5919 18 6
RPC VI, 6117 (temporary) Show 5919 20 6
RPC VI, 6121 (temporary) Show 5911 4 6
RPC V.3, — (number not assigned), type ID 80677 Show 152 1 5.3
RPC VI, 6126 (temporary) Show 5925 19 6
RPC VI, 6116 (temporary) Show 5916 5 6
RPC VI, 6117 (temporary) Show 5919 21 6
RPC VI, 6118 (temporary) Show 5924 2 6
RPC VI, 6121 (temporary) Show 5911 6 6
RPC V.3, — (number not assigned), type ID 80860 Show 190 2 5.3
RPC V.3, — (number not assigned), type ID 80821 Show 183 1 5.3
RPC V.3, — (number not assigned), type ID 81053 Show 187 2 5.3
RPC V.3, — (number not assigned), type ID 81236 Show 188 1 5.3
RPC V.3, — (number not assigned), type ID 81053 Show 187 1 5.3
RPC V.3, — (number not assigned), type ID 80720 Show 77 2 5.3
RPC V.3, — (number not assigned), type ID 80701 Show 85 1 5.3
RPC V.3, — (number not assigned), type ID 81174 Show 80 1 5.3
RPC V.3, — (number not assigned), type ID 80700 Show 88 1 5.3
RPC V.3, — (number not assigned), type ID 81000 Show 90 1 5.3
RPC V.3, — (number not assigned), type ID 80916 Show 91 2 5.3
RPC V.3, — (number not assigned), type ID 80914 Show 93 1 5.3
RPC V.3, — (number not assigned), type ID 81237 Show 191 1 5.3
RPC V.3, — (number not assigned), type ID 80675 Show 149 2 5.3
RPC V.3, — (number not assigned), type ID 80675 Show 149 6 5.3
RPC V.3, — (number not assigned), type ID 80712 Show 150 1 5.3
RPC V.3, — (number not assigned), type ID 80696 Show 161 2 5.3
RPC V.3, — (number not assigned), type ID 83833 Show 92 1 5.3
RPC V.3, — (number not assigned), type ID 80675 Show 149 5 5.3
RPC V.3, — (number not assigned), type ID 87002 Show 87 1 5.3
RPC VI, 6111 (temporary) Show 5908 6 6
RPC VI, 6117 (temporary) Show 5919 28 6
RPC VI, 6115 (temporary) Show 5910 3 6
RPC V.3, — (number not assigned), type ID 86045 Show 153 2 5.3
RPC V.3, — (number not assigned), type ID 80699 Show 159 6 5.3
RPC V.3, — (number not assigned), type ID 91431 Show 164 1 5.3
RPC V.3, — (number not assigned), type ID 81174 Show 80 2 5.3
RPC VI, 6126 (temporary) Show 5925 23 6
RPC VI, 6127 (temporary) Show 5917 2 6