Money is a strange concept. In some cases, the materials used to make cash, whether they are paper or coin form, are worth only a fraction of the value embossed on their faces. However, some situations such as historical significance, rarity or minting errors, some cash are worth more than their face value and affect coin values.

Here are some of the most expensive coins in the world:

1913 Liberty Head Nickel

The story behind this coin is that its pressing and minting did not have the approval of the U.S. Mint, which changed the piece’s design to an image of a Native American from Lady Liberty. Only five made it to public circulation, the most expensive of the coins sold for $3.7 million.

1343 Edward III Florin

This is a rare coin since its minting dates back several hundred years ago. This valuable coin is only one of three types known to have survived for centuries. Its worth is approximately $6.8 million.

1787 Brasher Doubloon

The story behind this coin is that a talented goldsmith, Ephraim Brasher, petitioned New York State to mint a new set of copper coins in 1787. However, the state did not want Brasher’s work or his copper coins. Brasher ignored the decision and minted the coins anyway. Most of the coins were in bronze but a valuable few were in 22-carat gold. A Wall Street investment firm bought one of the doubloons for approximately $7.4 million.

1907 Saint-Gaudens Double Eagle

The complicated design of Augustus Saint-Gaudens proved to be a difficult option for the U.S. Mint to produce for commercial circulation, which resulted in a change of the design. Charles Barber, the chief engraver, chose to strike the words “In God We Trust” from the design instead of removing anything from the previous one. The mint produced the coin, but it is now a rarity. This coin is approximately worth $7.6 million.

1933 Double Eagle

This coin is an example of changing coin values because of circumstance and history. The 1933 Double Eagle made it into production but never reached public circulation. Franklin D. Roosevelt banned anyone from owning gold as an attempt to stop the banking crisis in the U.S. during that time. Twenty slipped out and are approximately worth $7.6 million.

These are some of the most expensive coins in the world. Coin values go beyond their minting value because of various factors.