The ring gold dollar of 1852. This was an attempt to make the gold dollar slightly larger than the current regular issue.
This design is actually struck using the reverse die of a dime with the other side blank with the exception of the denticles.
There are at least 4 known as follows per Akers Gold Pattern book:
2) DeWitt Smith, V. Brand (journal id #46971) to Horace Brand, Boyd, Judd, Wilkison, Paramount, Superior 1/08 - PCGS65.
3) Sloss, 79 ANA
4) Sloss, 79 ANA
The Merkin 4/70 example may be a fifth. One is ex Olsen (Mehl 11/44 lot 91A).
A companion gold half dollar struck using half dime dies also was made as J135/P162
Image courtesy of the National Numismatic Collection of the Smothsonian Institution.