This is the famous and unique 1913 Type II Buffalo nickel struck in copper. This used to be J1790 in earlier editions.
It was supposedly struck as a business strike on a planchet of 95% copper, 5% nickel and zinc. Pollock delisted this as possibly being a mint error. It has now been discovered that it is a regular circulation piece that was copper plated and will thus be delisted in future editions of Judd. The reason for the plating is unknown.
The history surrounding this piece is below.
This unique piece was originally housed in a leather case with the 5 1913 Liberty nickels, an example of J1950/P2024 (this used to be J1789 in earlier editions) and a regular 1913 type II. It has the same pedigree ex Samuel W. Brown, August Wagner, Stephen Nagy, Wayte Raymond, Col Green and Burdette Johnson and Eric P. Newman.
The piece was offered as a copper trial to A. Kosoff (Numismatic Gallery) in an 11/14/46 invoice by B.G. Johnson but was returned. The coin and the case are now in the possession of the Eric P. Newman Numismatic Education Foundation.
For additional information on this piece, we recommend the article "A Forgotten Nickel & Its Companions" by Jeff Reichenberger in the September 2011 edition of the Numismatist.
The image above is of the actual piece and is courtesy of Eric P. Newman and Jeff Reichenberger.