Nickel error? 1970 s

Itried to get good pics i hope these help but can anyone tell me what causes a nickel to have raised center edge both sides of edge are lower

 

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My First guess would be "Encasement" of some kind, like in a Good Luck holder.

 

That's what I thought also. Some type of coin bezel damaged the rim.

 

Huh so not an error still pretty neat though its really deep set and looks cool think ill keep it as a charm maybe myself