sorry - no added value ...many clad coins that are in the ground for a extended period of time turn color like this. alot are found with metal dectors, cleaned off and spent. It looks like yours quarter has some dirt on it ?????
It's pretty hard to tell with those pics, sorry. Try to post up some closer, bigger pictures, preferably with a black background for contrast. Oh, and a picture of the rim (which may be tough to get) Also, welcome to CoinTalk!
I can't be certain either. Try to get some bigger, clearer pics. And as silentbiolent said, the rim would be a major help.
