What a strange coloring in coin roll

I was going through a roll of dimes when I found this what looks like a black & gold, or black & copper one, what causes this? And what is it?

 

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It is probably toning affected by environmental or chemical conditions.

Chris

 

Environmental damage... it was exposed to something in the air, the soil, etc.

 

Clad coins and even nickels change a coppery color when exposed to the elements.
Here are some of my metal detected examples

 

That 1984 p dime in your 2nd picture is match in the black color but mine has some gold coloring too and I found mine in a roll off 2017 dimes