 | The first double eagle was minted in 1849, coinciding with the California Gold Rush. In that year, the mint produced two pieces in proof. The first resides in the Smithsonian Institution in Washington DC. The second was presented to then Treasury Secretary William M. Meredith and was later sold as part of his estate - the present location of this coin remains unknown. |  If found the coin would very easily bring seven figures. |
 | This 1804 silver dollar was not, in fact, minted in 1804. It was pressed 30 years later as a mix-up when minting dollars as gifts for Asian rulers on trade envoy visits. Six are known to exist. Sold by auctioneers Heritage Auctions, an example sold for $3.7 million at auction in May 2008. |  |
 | The one-cent copper coin was made in 1793 and is one of the very first pennies ever struck by the United States Mint. The coin sold for $1.38 million at a Florida auction in 2012. |  |
 | This coin was struck in ancient Rome to commemorate the March 15, 44 B.C. ("Ides of March") assassination of Julius Caesar. Brutus issued a series of gold and silver coins commemorating the event. Only two gold examples are known. |  The silver denarius coins in good condition have sold for over $ 500,000 |
