Identify: Bronze Constantinopolis Mint Ancient Coin

I have a pendant made with sterling silver that is around what looks like an ancient bronze coin. The only confidence I have is the CON at the bottom on the reverse is supposed to be a Constantinopolis mint. I've found many images of a similar coin with the large M on the reverse but can't find any with a cross above AND on the right side (most have a star on the sides).

It weighs 21.9 grams but that also includes the silver bezel and also because of the bezel, I can't get an accurate thickness (definitely over 3 mm). It's not an evenly round; the diameter varies between 26.8 mm and 28.3 mm.



I can see some similarities with https://en.numista.com/catalogue/pieces111130.html but I know it is not the same coin.

Is this a made up replica? An actual coin? If the latter, where can I find details and possible value?

Thanks, all!

Yes, a Byzantine bronze follis (40 nummi) minted in Constantinople. I see no reason to doubt its authenticity. You can check the Wildwinds databank of Byzantine coins (http://www.wildwinds.com/coins/sb/i.html) to look for a match, or perhaps someone more knowledgeable than me on Byzantine coins will chime in here with an attribution.

Note added later: I searched the page cited for "star left, cross above, cross right" and only one coin matched. This is SB 63, Justin I, AE follis, 518-527 AD. I think this might be your coin - see what you think