Not many places made copper coins that small. I see the bust you are talking about, but given the overall condition of the coin, I think this may be another instance of "Jesus in the toast" if you will.
If it is indeed a bust, my best guess is some sort of barbarian coin. I have a 6mm coin that was supposedly found among 4th century barbaric minims. The style is wrong though--those are usually laureate or radiate. While copies of the helmeted bust "Victoriae Laetae" exist, they are pretty close to the original size.
India cranked out some small coppers, but the only one that small with a bust would be Indo-Parthian king Gondophares, and the bust style is wrong.
If it is indeed a bust, my best guess is some sort of barbarian coin. I have a 6mm coin that was supposedly found among 4th century barbaric minims. The style is wrong though--those are usually laureate or radiate. While copies of the helmeted bust "Victoriae Laetae" exist, they are pretty close to the original size.
India cranked out some small coppers, but the only one that small with a bust would be Indo-Parthian king Gondophares, and the bust style is wrong.























