The macro setting on my phone camera is pretty lousy, but here is the edge to a 2007-D Montana quarter (ninth down from the top). It weighs the same as a normal clad quarter, so I'm guessing it's not actually silver. Has anyone else encountered this? I stumbled upon a gold plated Mass. quarter not long ago, might this be silver plated? Thanks!
I was at a flea market today and got a 2005 P Oregon quarter back to day that looks like a silver coin as well.
Many of these were plated and then sold by third party businesses who plated them in silver, gold, etc. The plating shouldn't add very much weight so simply weighing the coin will tell you if it's plated or not. But with San Francisco minting all the silver proof coins I think that an actual P/D silver mint error would be extremely unlikely to be found, although I suppose there is a chance that maybe some S mint errors could possibly exist.
