The Nickel Error is sort of similar to a Capped Die Strike. However, where a Capped Die Strike is due to a previously struck coin sticking to the Hammer Die and becoming a Die for the next coin fed into the Striking Chamber, your' coin was struck only by the Obverse Die and not a previously struck coin on the Reverse due to two Planchets accidentally being fed into the Striking Chamber. This resulted in your' coin having an Obverse image while the other coin has the Reverse image. It would be nice if you could find the missing one to the pair! Pairs are hard to find but not impossible and when found, they are most often certified, graded and holdered together which makes them much, much more collectible, sought after and valuable.