In the year 2000, the US released a newly minted dollar coin for public circulation called the Sacagawea dollar, named after the Native American guide that crucially assisted the famous American explores Lewis and Clark. It’s colloquially known as the golden dollar, but it contains no actual gold.
Rather, the Sacagawea dollar gets its trademark golden color using a copper core clad by manganese brass (this also explains why the coin is relatively light). Of course, the face of the coin bears an artist’s interpretation of Sacagawea (no contemporary image of the real Sacagawea exists) and the opposite side of the coin has undergone several design changes over the years. However, several thousand coins were once minted with a very curious error.
Shortly after the Sacagawea coin was released to the public, a small batch was discovered in a bank in Arkansas with a major design error. Instead of Sacagawea’s portrait, the coins were mistakenly minted with the same design as the US state quarter and featured George Washington instead.
Such an error was not unheard of at the time. Coins mistakenly minted with the wrong design are known as “mule coins” in the field of numismatics and are highly sought after.
The faulty coins were traced back to the Philadelphia mint where they were immediately impounded to keep them out of circulation. The coins that did manage to reach circulation are considered very valuable and have sold for as much as $200,000 apiece.
That’s a large sum for a non-gold coin!