You've probably never seen a U.S. coin like this before. The U.S. Mint began experimenting with different gold dollar patterns in 1852. The problem was simple, gold dollars were small and easily lost. And so the Mint tried out creating pattern gold dollars in 1852, producing the patterns now known as Judd-136 to Judd-148 which have a larger, more convenient diameter.
Instead a more practical solution eventually was decided on. The amount of . . .
Full story at: Luxist
"This 1849 example hand-engraved by James Longacre in the upcoming Heritage Auction shows they were experimenting with gold dollar patterns prior to 1852." - A.C. Dwyer