Maybe I need to get better lighting....it is a pure pewter colored quarter all the way around. Very cool looking.
Underlying circumstances could discolor a quarter, and I proved it. Even the acid in a BUTTERFINGER candy bar, if left a chunk of chocolate on the surface of a brand new Quarter, over a period of 25 years discolors it to a "Butterfinger Bronze color". Other things besides acids are heat. Carburizing flame can blacken a quarter (permenantly).
The MS-64 1990-P quarters I had appraised, and also slabbed through my membership at PCGS, are the same as the one I sample/tried this trick. The coin is still MS-64 1990-P, but with the same color of chocolate (I named Butterfinger Bronze). If you'd like to see, it only stained the surface permanently, but not damaged it. "Ask if you want to see it, or up close photos of it". I have some 25X powered microscope photos around here somewhere of it.
Thanks, looking to start a Butterfinger Bronze stained Quarter thread... Woulkd you like an invite via thread to be posted to your timeline @mynamespat ?