1999 pennsylvania quarter error
Truly a one of a kind find there were three Pennsylvania quarters minted and One was a experimental type and was made out of a material called MANGANESE planchet which also has a green hue color to it, the other were made of platinum, 24kt gold and one of silver proof, as you can see this one is most likely a one of a kind look up on internet and see for yourself, a must have for error collectors or collectors in general.