One of the rarest American coins, the 1787 gold Brasher doubloon, recently sold for $7.4 million. The coin was sold by Blanchard and Co., a coin and precious metal dealer located in New Orleans. It was purchased by a Wall Street investment firm for a non-disclosed client.

When the Brasher doubloon was first released, the nation had yet to establish a standard currency, and state mints produced mostly copper coins. The coin, which earned its name because of its proximity in size to the Spanish gold doubloon, was made by Epraim Brasher, a goldsmith who happened to be George Washington's neighbor. He and John Bailey petitioned to reverse New York legislature against issuing of copper coins. After they failed, Bailey continued to make copper coins privately, and Brasher went on to create what is now considered "the holy grail of all collectible coins" by most avid numismatists, including John Albanese. Albanese, a consultant for the Certified Acceptance Corporation, said that his offer of $5.5 million for the coin was rejected three years ago.

When it was first minted, the coin was worth about $15. Now, its 26.66 grams of gold make it worth $1,500 in this precious metal alone. It's distinguished from the five other known doubloons by the hallmark punch on the eagle's breast. The others feature the punch on the left wing.

The coin, which is smaller in size but heavier than a half dollar, was sealed in a protective case and surrounded by three guards at Blanchard's headquarters until it was shipped off in an armored vehicle over the weekend. This recent sale is their most expensive to date, however, Blanchard's has dealt a number of other historic sales, including a 1913 Liberty head nickel that went for $3 million.