a filled die error more than likely from the description,, a very common type of error that adds little value to the coin, but yes a real error . Rick
I'm just guessing here, but I think you are talking about some kind of U.S. coin with indistinct letters in "LIBERTY" and the "IN" of "IN GOD WE TRUST". If the coin is well circulated, it is probably just showing wear. If it is uncirculated, or nearly so, it is probably what is called a "struck through grease" example. What happens is that grease gets into the die, and partially blocks the coin metal from moving into the incuse areas of the die. You would probably get a more precise answer in the Error Coins forum, but my understanding is that "struck through" coins don't carry much, if any, premium unless they are really spectacular.
