DDD quote from ==> http://www.doubleddie.com/144843.html "Die deterioration doubling is another form of common, worthless doubling found on U.S. coinage. Like mechanical doubling, it is frequently mistaken for the doubling that is seen on genuine doubled dies. Unlike mechanical doubling which is formed while the coin is being struck, die deterioration doubling is actually on the die itself. That is the one thing that it does have in common with genuine doubled die doubling. Die deterioration doubling results when the dies used to strike coins are kept in use for too long a period of time." … and more to read from the link above ….. ==> https://en.wikipedia.org/wiki/Die-deterioration_doubling
