Extremely rare Continental silver dollar. In fact it’s so rare that only two of them are known to exist (there are others in pewter and brass). This was made sometime in 1777 when Congress was debating the switch from paper currency to hard coinage, but they never had enough silver on hand to make it a feasible project.
It’s thought that the design was done by Franklin. The top image has the Latin inscription Fugio with the English translation of “Mind Your Business”. A better translation might be “time flies, so mind your business” (which is why an image of a sundial is also engraved on that side).
The other side features the motto “American States: We Are One”, with 13 interlocked links, representing each of the colonies (each of whom is named on one of the links.
This coin sold for $1.4 million last week.