Image courtesy of Goldberg Coin Auctions

"It's so small." Most of us have all heard this expression at one time or another. It might be a dealer describing a nick, scratch or spot on a coin he's trying to sell to us. Or the woman of our dreams whispering this after she sees the diamond ring we've just proposed to her with.

Well, legend has it, something similar occurred with the unique 1870-S Half Dime. A customer who was interested in this coin made special arrangements to try to purchase it. When the customer finally saw the coin, his initial reaction was "but it's so small." And he decided not to purchase the coin, or so the story goes.

The 1870-S Half Dime is one of a handful of U.S. coins in existence having the honor of being unique for business strike coins and in private hands. Not only is the 1870-S Half Dime unique but it is also one of America's most mysterious coins.

In 1978 at a convention held by the American Numismatic Association (ANA), an 1870-S Half Dime appeared in an exhibition for the first time in numismatic history. The coin is believed to have been found 108 years after its issue at a coin show inside a dealer's junk box and purchased by a customer as a regular 1870 Half Dime. The owner of the coin offered the 1870-S Half Dime to a big dealer at the Coinfest show. The dealer and seller then agreed to trade the coin for a $25,000 premium of the hammer price of an 1804 Dollar that was being offered at one of the auctions taking place during that show. The 1870-S Half Dime finally traded at $425,000.

There is evidence indicating there were six 1870-S Half Dime dies at the San Francisco Mint, but no documentation indicates these dies were actually used to strike any coins. However, in 1870 the San Francisco Mint, then called the Granite Lady, was on the verge of being built. According to U.S. Mint documents, to commemorate this event, the San Francisco Mint struck coins for its cornerstone display. This is the only documentation mentioning the existence of an 1870-S Half Dime being produced, but it was for the San Francisco Mint's cornerstone only and not for circulation. It is not known whether more examples were produced and if so, how and under what circumstances. There is the possibility that more coins are out there waiting to be found just as this one was in 1978.

So for over a century, this coin was believed to be non-existent except for one coin in the San Francisco Mint's cornerstone. There are so many unsolved mysteries surrounding the 1870-S Half Dime, making it one of America's most legendary coins. In the past, other legendary coins such as the 1933 Saint Gauden's Double Eagle, 1804 Dollar or 1913 Liberty Nickel have sold for millions of dollars even though they are not unique. The 1870-S Half Dime is a prime example of a rare yet undervalued coin with considerable history attached.