Charles Barber's 1906 Liberty Head pattern double eagle. The reverse with Columbia standing in front of an eagle was copied from an 1891 pattern half dollar J1766/P1980.
The edge is lettered E*P*L*U*R*I*B*U*S*U*N*U*M*. This edge device was later used on some examples of the famous 1907 St Gaudens extra high relief J1907/P2001. This used to be J1778 in earlier editions of Judd.
Only a single example is known. It and a gilt copper obverse splasher JA1906-1/P3524 are in the Smithsonian.
Photo courtesy of the National Numismatic Collection of the Smithsonian Institution.