Found it in a Machine wrapped roll of fresh 2020 dimes.It doesn't look like environmental toning to me and has the right look of a partial clad strike.Hard to take pictures since the color is really light sensitive.Its in a Cresent shape with a light brownish pinta with some breaks in color within.It doesn't go over the rim but maybe a little bit and the edge looks normal. I Can't weigh it but take it to a nearby coin shop.Or if not then it could be a improperly annealed planchet.
Its quite difficult to photograph I tried my best.Don't think its residue but that's why these are tricky.
I can't see anything with these photos, but it doesn't appear to be any kind of traditional partial missing clad layer. I am sure there are sections where the clad is missing but that could be after the fact. Try to photogragh it with another coin as a control, and perhaps a white (or black background). Try natural light.