1970 Roosevelt Dime. Error? Damage? Something Else?

[blauer]

As soon as I received this dime as change, I knew something was up with it. I took the loop to it, and this is what I saw:

The obverse (at least the rim) appears very thin and separating a bit from the core; to the extent that I feel I can slip my fingernail under and peel it off. The gold color on the coin is also strange to me. It doesn't look like toning but more like a partial layer of gold plating.

So, my question to everyone: Is this an error, damage or something else?

Thanks

 

[cudamark]

Environmental damage.

 

[TreasureCatto]

Known as a "Sandwich" coin. Copper band of edge corroded from acid bath. Pmd for sure.