I think this is my smallest LRB with something clearly recognizable. This coin is 7mm and weighs .6g. and has a pretty clear Chi-Rho on the reverse. on top of a dime for scale the obverse is not clear and has what looks like glue on it, so I am soaking it in acetone.
One of my recent additions has Victory inscribing Chi-Rho XP on reverse. The coin was struck at Antioch under Roman Empress Aelia Flaccilla. But the weight is 4.5 g.
It might be a Justinian AE4 of Carthage like this one: Sear 283. 9 mm. 1.24 grams. Struck 548-565 according to the Dumbarton Oaks Catalog.
Interesting coin, Victor. I admit, if I saw it, I would just ignore it and move along. The obverse is just too gnarly. Maybe it will look better when you're done with it.