I came across an XF 1954 Lincoln cent with an odd pattern of, for lack of a better term, flow lines. Below are some pictures. It is most extensive on the obverse - about like the area between the "R" and the "U" on the picture below for about 3/4 of the circumference and some lighter on the remainder. It extends up onto the bust at the bottom, and there are a few small spots around Lincoln's chin and forehead. There is a bit on the upper quarter of the reverse and it is somewhat lighter. For what its worth, the metal appears to be drawn in from the rim, rather than being pushed toward the rim. I would love to know what caused this. Any ideas? Here are the pics:
