Be sure to select "original" view; it gives you a nice 2265x800 view (without a huge file).

A "Die Clash" occurs when a coin planchet misfeeds and the two dies bang directly together. This sometimes leaves an impression from one die on the other. For instance, a portion of the obverse pattern may transfer into the reverse image, or vice versa. Then, when subsequent planchets are struck, they get the transferred image. Die clashes are common in 19th century American coinage, especially Morgan dollars where multiple clashes may leave several transfer images on subsequent coin strikes.

But this coin came as a great surprise to me. I set out to photograph an example of arguably the most beautiful US coin, the Walking Liberty half dollar. Adolph Weinman's design was adapted for the Silver Eagle but without his superb eagle, which is only found on the half dollar (1916-1947). This particular example, a 1941(P), was graded and slabbed MS-66 by NGC.

In the reverse photograph I noticed a raised line on the eagle's shoulder that should not have been there. Although it looked initially like a broken die mark, the raised triangle between the wings showed it to be a die clash mark. I have highlighted and lightly colored this section in the center photograph. This mark is transferred from the bottom hem of the obverse skirt as it swirls and rises. Likewise, on the raised parts of the obverse a very faint impression of the eagle's feathers can be seen at high magnification.

That fact that this occurred in such a sharply-struck specimen implies that the clash occurred early in the life of the die set. That means that many coins could have been struck with these clash marks before they were noticed and corrected.