Advice please....

[Smoogle]

Hi,
Saltwater environment find:
basically - what should I do to clean and ID it? what would it be made of? please leave a link as no doubt this has been asked before...
also it is very thin, pic is with an Ausiie Florin I also found on todays hunt - are some coins this thin
Thanks........

[l.cutler]

Some are that thin, but I think that one is just corroded away. If it is, there is nothing you can really do for it.

[Smoogle]

Thanks I.cutler , yes stevemc suggested it has been bouncing around and getting "Thin", I pulled it from absolute beach bedrock after a significant storm eroded a beach near me ...... - weird thing is my eyes are just straining to make out features of a coin and I'm still optimistically curious........ it is perfectly round and under a penny diameter by about 1 - 2 mm evenly all around - of course if it did not start life as a thin coin - all features are lost.....
more treasure to us all