By the way, I was pleased with the photography 'breakthrough'. The white balance needs to be tweaked, that's a useless (now useful) slab beneath it. It's still MUCH better than what I was getting before. The coin itself is dark and not the easiest to photograph. I used a soup can, put my phone on top, and used 'pro' (raw) mode. I grabbed a Poseidon collection slab and made it the bottom. While cleaning junk off of the 'photography' area, I misplaced the small coin capsule that was to be the spacer. I'm unsure what the object to the right of the reverse M is, and thus the Sear number. Do youthink that's an E officina? I'm not sure what's going on there, it looks almost like an X. Sadly I never invested in a scale but this is unusually light for a Justin. Before I looked closely at it I thought it might be a small module Anastasius. It's about the same size as a Justin II follis, and the JII had slightly more heft. Do you think it's a contemporary imitation?
While looking at it, I now am of the opinion that the object to the right of the M is a crescent, like so ). Opinions? I'm not quite sure what's going on with the officina. Vcoins Nikomedia folles of JustinII are coming up as 10-13 g., with 12-13 being the norm. Based on heft, this is probably c. 10 g.
I'm glad you received some help, because I am completely clueless when it comes to Byzantine coins. I could have confirmed that yes, that is a Byzantine coin in your post, but that's as far as my knowledge would have taken me.
I am quite sure that the officina for this follis of Justinian I is Γ (third officina). The mint is Constantinople. There's just enough of the N (CON) visible to confirm that this is the mint for this coin. I thought it might be from Antioch, but I ruled that out. There seems to be an inverted crescent to the right of the M, cross to the left, like this example: https://www.ebay.com/itm/395791658799 But that's a guess on my part. Your coin might be a very scarce variety, definitely worthy of further research.
