It is a 11th/12th century coin. I have run across them in tetartera groups , I am not sure if they are found together but they are paired together because of size and weight
I checked the following to see if I could find any info.
Coinage of the Latin East Metcalf
( Same as coinage in Balkans but updated and more plates.)
Coinage of the Empire of Trebizond
. Simon BendallRatto
coins a Beginners Guide by Paul Torongo
Coins of the Crusader
States by Alex Malloy
( Just the plates.)
I could not find a match, in any of these books.
I think it was related to tetartera but as an imitation of the currency but not a particular coin. Granted this is just an educated guess but if anyone else has any info it would be great to find out more.