What kind of error is this?

When I came across this coin it caught my eye. At first I thought someone had melted a blob of something on it. Then I notced the uniform color throughout.
It must have came from the mint like this?
I can't find any information about this type of error.
I would guess this is pretty rare?
Any suggestions?

 

Log in or Sign up to hide this ad.

Post mint damage, not an error.

 

Not rare
Post Mint Damage
Came in contact with corroding chemicals

 

I believe it was exposed to extreme heat which caused the clad layer to become deformed... Not a Mint Error

 

We all can assure you that your dime
did not leave the US Mint looking like that.

 

Thank you.
That was my first thought on this coin. But, why is this not discolored?
It appears to be coated and colored the same around the entire coin. That is why I thought it might have went through the mint process.

Thank you for your expertise.
I've been learning about and collecting coins for only a year now. Learning new things daily. Thanks

 

No, it just means it had time to tone since it happened.