Authentic Atocha Reproduction?

I dunno, maybe you could get it XRFed.

https://www.google.com/search?q=xrf...f-8&oe=utf-8

Authentic or not, being an avid cob collector I fail to understand why people would want to waste their money on such stuff in the first place.

These are the only Mel Fisher reproduction coins I can find that are made from remelted Atocha silver. The Taffi Fisher collection, made using a bar from the wreck. All look to be mounted as jewelry. It says they're cast, so I'd expect them to be shiny and not as sharp looking as a struck cob. I wouldn't expect to see any of the characteristic edge cracking, and the edges are probably pretty well rounded off to make nice jewelry. The cobs that are reproduced are prime quality examples, well struck with full details and lettering, and are a lot better looking than most authentic cobs.

http://store.melfisher.com/collecti...r-collection

If your coin looks EXACTLY like any of these, then you probably own an authentic reproduction. If it doesn't match it's probably a reproduction made using ordinary sterling silver.