Well it seems like everyone else besides me is finding something strange... This quarter belongs to a co-worker that wanted me to tell him why it looks like this, as if I would have any idea, lol. The obverse is a dark copper tone that shifts to pink, blue and purple at different light angles while the reverse is bright copper tone that shifts to a pink and purple closer to the edge. (I'll try to post some gifs) To me it looks like it was chemically stained with something. I guess it's possible it could be improperly annealed /sintered but I have no idea how to identify that since they all look different to me.
Well I started to use metal ones but I didn't want to get yelled at so I used a pair of plastic disposable ones, lol
The nice thing I like about the tongs in the image I posted is that they are "self-locking" which means that you can take a photo of the edge of a coin and remain hands-free to hold and focus your camera.
That reminds me, I forgot to post the edge shot. I got caught up in making gifs, lol. The main reason I was asking about the quarter was the reeding was still silver and shiny. Your right, self-locking would have been really handy getting this edge shot. I finally gave up and propped it against a couple of other quarters.
Some type of post mint damage, not a mint error. There's no way to really tell for sure what someone did to it.