I couldn't find any information on this coin so I thought this would be the best place to post. The coin is very small, smaller than a dime. The eagle that would usually be the tail side appears to be the head because it has stars around it and the date under it (1840). The opposite side is completely smooth and blank, and has a small rectangular indent in the center (I would assume from the pressing?). Can anyone identify this, and is the blank side an error or something else?