I've never found and error coin before...and I'm not well diversed in what constitutes an error coin or not. Is this one? Looking at the E and the 'USU' of the motto or whatever it is.
Hi, Congratulations! It is indeed what is called a "Struck Through Grease" Error. That is the good news, The not so good news is that this type of error is probably the most common there is. There is not much of a premium paid over face for one this slight. It is an error though! have Fun, Bill
While it may be a "grease strike" it might just as easily be a failure to strike up properly. This part of the reverse design lies opposite the highest part of Roosevelt's head, hence a relatively deep recess in the obverse die face. Such areas are prone to weakness as the metal preferentially flows into the broad recess of Roosevelt's head. Weakness in this area of the reverse design is quite common.
Also..on the other side of the same quarter posted above.... The 'Y' in 'Freedom and Unity' is barely noticable...and there is a cracked die error running through the bottom of the tree on the right.
