Not a ghost, probably an asteroid.
I think those 'bubbles' are from a worn die that has a little gouge in it so when it stamps the coins the opposite -- a 'bubble' -- shows up. OR...maybe some chemical reaction...but I doubt it since you found another.
I think those 'bubbles' are from a worn die that has a little gouge in it so when it stamps the coins the opposite -- a 'bubble' -- shows up. OR...maybe some chemical reaction...but I doubt it since you found another.





















