Can you give us a better photo of both sides of the dime? Don't forget to "Crop" and "Resize" before posting them. As for the quarters, I would say, "No!". Chris
Just coins that were buried for a very long time. Environmental damage. I have been metal detecting for a few years now and most of the dimes, nickels and quarters that have been buried for some time look just like yours.
Sand, soil, dirt, clay.. anytime a coin is buried for a period of time the elements take thier toll on these helpless little fellas