I was counting money at work and came across this Sacagawea dollar
coin. I always buy dollar coins I find so I did the same with this one. When I got home and actually got to look at the coin it appears there may be an error on the reverse. It almost looks like there is a small raised "moon" just above the eagle. I have searched everywhere and can't find anything similar. The coin doesn't appear to have much damage to either side. What do you all think this could be?