1: 1. The 1943 Copper Penny Rare and elusive, the 1943 Copper Penny remains a mystery. How did a few pennies minted with copper instead of zinc alloy end up in circulation?

2: 2. The Missing Silver Dollar The whereabouts of the 1804 Silver Dollar, known as the "King of Coins," is unknown. How did all known specimens disappear, leaving collectors puzzled?

3: 3. The Disappearing Nickel The 1913 Liberty Head Nickel is one of the most valuable coins, but how did five illegal specimens surface decades later, leaving experts wondering about their origin?

4: 4. The Stolen Double Eagle In 1933, the U.S. Mint halted the Gold Double Eagle production, but some were stolen. Where are the remaining 1933 Double Eagles, and whom do they belong to?

5: 5. The Mysterious Dime Featuring Lady Liberty on the front and an oak branch on the reverse, the 1874-CC Dime has only one known surviving specimen. Why are there no others?

6: 6. The Damaged Buffalo Nickel Known as the 1918/7-D Buffalo Nickel, this coin exhibits overdate characteristics. How did this rare error coin end up with a significantly damaged "7" on its date?

7: 7. The Lost Brasher Doubloon Ephraim Brasher's 1787 Brasher Doubloon is a legendary coin, but many believe additional specimens remain hidden. Will new discoveries shed light on this mystery?

8: 8. The Intriguing 1942-45 Philippine Coins During World War II, the Philippines produced unique coins made of shell casings and other unconventional materials. Where have these wartime coins disappeared to?

9: 9. The Uncirculated 1950-D Nickels Though the U.S. Mint claims not to have minted any 1950-D Nickels, a few remarkable, uncirculated specimens have been found. How did these coins enter circulation?