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Clearly defined strikes are a clear giveaway that this error coin is a fake.With a mintage of over 4.3 billion (with a "B!") coins, the 1976-D
Lincoln Cent is not exactly a specimen one would expect to be counterfeited. In fact, they have a melt value of nearly 2 cents, so creating fakes for use in commerce would not be the smartest idea.
Read More: Counterfeit Detection Series.
Numismatic Guaranty Corporation (NGC) graders recently caught a very interesting (and spurious) 1976-D cent that had been submitted for grading. As you can see, it is not your average counterfeit. Instead the forger has struck what possibly was a genuine 1976-D
Lincoln Cent multiple times with a counterfeit die. Those extra strikes seem to have been created by misaligned dies, as they mostly appear on the right side of the coin.

The extra strikes appear to have been created by misaligned dies.The biggest issue that any mint-error expert would notice is the strength of each strike. When a cent is produced at the U.S. Mint, the presses exert about 35 tons of pressure to fully execute a design. A genuine multi-struck example from the mint would show more of a "ghosting" of the previous hits, as most would be obliterated. This didn't happen on this coin, however, as it was struck with far less force.

The counterfeit displays dates that are too clearly defined and raised marks around LIBERTY. The reverse features similar doubling.
The photos here reveal many concerns. First, note how clear all of the duplicate dates are. As mentioned, these are much more visible than they would be on a genuine example. Additionally, a number of odd, raised die scratches and toolmarks appear in the fields around LIBERTY. It also is strange that there is no evidence of extra strikes on that portion of the coin. These effects are quite obvious on the reverse as well.
As is the case with any specialized area of numismatics, it is often better to leave authentication to the experts. Coins encapsulated by NGC, including mint errors, are always guaranteed to be authentic.