Coin counterfeiting

Coin counterfeiting of valuable antique coins is common; modern high-value coins are also counterfeited and circulated. Counterfeit antique coins are generally made to a very high standard so that they can deceive experts; this is not easy and many coins still stand out.

Counterfeits of higher-value coins in circulation, designed for general circulation at face value, have been made by criminals for thousands of years.

For modern coins in general circulation, the most common method of protection from forgeries is the use of bi-metallic coins made of two metals of different color, which are difficult to counterfeit at low cost. The most common way of forging these coins is to change the area that should be a different color by painting it; however, the paint is often easy to scratch off and the coins soon look very crude once worn. An increasing number of coins are cast from the same composition alloy as the real coin, but have poor reproduction of details such as the milling on the side of the coin and the stamped lettering. When the euro was introduced into Europe, there were initially very few counterfeits; however, the number increased massively as time went by. The high and increasing number of fake euro coins in circulation in 2004 led to the creation of a Technical and Scientific Center for the coordination of technical actions to protect euro coins against counterfeiting. It was estimated that 3.04% of all UK £1 coins in circulation are counterfeit. Between 2002 and 2006, approximately 400,000 counterfeit euro coins were removed from circulation; however, "the overall number is very small by historical standards and by comparison to the 69 billion circulating (genuine) euro coins"

A well known and popular numismatic item is the 1944 nickel counterfeited by Francis LeRoy Henning. Unlike official specimens, this spurious item is missing a large mintmark for the Philadelphia Mint. Because of a different wartime composition, all nickels of this period had large mintmarks. Normally the Philadelphia mint would not have included one, but in 1944 all of its nickels had a "P" above the dome of Monticello. It is estimated that 100,000 of these coins were placed into circulation. Today they remain readily available to collectors.

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