I originally thought the same thing as you jloring. The diameter is actually less than a standard Wheat Cent. It is about 1/3 the thickness of a standard Wheat Cent. Most of the motto/devices are still somewhat visible within the perimeter. But as Conder101 & LostDutchman have suggested , it was probably exposed to some kind of acid , which would definitely explain the mushy appearance. Thanks folks for the replies.