2010 D Dime Found In Penny Roll

Yes it happens with dark toned Dimes that look like copper cents .

Lol T-Bop

Cool...if we could un-nail it though for a sec, just so I can be clear, which type of environmental damage is it that blackens part of the clad and shows the copper layer in other parts, while remaining unpitted and not removing lustre though?

just an un-intentional accident when sorting out the coins.

Of that, I believe you are 100% accurate Dearborn

the glass half empty types instead wonder about the 49 dimes that got away

Yes Silviosi, and I do apologize as I see the photo came out blue on the obverse photo. The Reverse photo captured the dark color better, which is a dark grey. Like a deep shadow, but not quite black. Some clad extends to either side of the dark areas and on the high flat areas of the devices, and the rest of the reverse is a copper tone that in places reminds me of a penny that has been cleaned, more pink than orange if that makes sense. The obverse is mostly the darker grey color, with again clad on the highest spots of the devices, and the copper tone in the lighter area at the field to the southwest of the bust. Even the dark areas and copper toned areas have a shine, while the clad areas display lustre.
I do appreciate all of the input, whatever y'all think it is will be how I label it.

Environmental toning/discolouration. Nice profit!