Russian Seal, Image by StuE, Found by DaveCC.
Found in the Colchester area.
Possible Russian seal or neighbouring country that uses Cyrillic script.
Both sides look to have a continuous circular border. One side has a star at the top with two rows of writing beneath the letters tentatively translated to their Latin equivalents read, MIR?I? and beneath PANOVN.
The other side has 3AI?INA curved above VBS straight across the middle and another word curved around the bottom beginning AI?