Die deterioration doubling

Die deterioration doubling, or DDD, is an extremely common form of degradation on many United States and Canadian coins. Many beginning numismatists buy coins they thought were very valuable, but really aren’t worth more than a little over face value due to a die deterioration doubling. This common error fools a number of people into believing it is a much rarer, and more valuable, form of doubling. It goes by a number of names, such as "poorman’s double die."

Due to a combination of improper preparation of the dies used to strike the coins, excessive wear while striking the coins, and overuse by the Mint, die deterioration doubling has occurred on nearly every series issued by the mint in recent times. Certain coins are more susceptible to it than others, due to various factors, but it occurs on most coins. One of the first, and largest, factors which contributes to Die Deterioration Doubling is improper treatment of the steel dies used to strike coins. In order to understand how this works, it is necessary to review the basic steps in making a die.

Making a die

See main article:Die making

Identification of Die Deterioration Doubling

Die Deterioration Doubling is caused by a few simple things, but it can be difficult to positively identify. There are a number of different things which appear similar, but the characteristic traits of each are easy to identify with practice. As discussed earlier, Die Deterioration Doubling is often mistaken for Hub Doubling, but a few simple diagnostics will generally make the difference clear.

The causes of Die Deterioration Doubling and Hub Doubling are different, but their appearance on the finished coin is often similar. Die Deterioration Doubling appears most often around the mintmark and date because they are alone in the field. When DDD occurs in other features, like the bust of Jefferson, it looks more like a weak strike than doubling. Close examination of features affected by Die Deterioration Doubling shows that it is extremely irregular. This is because the metal does not flow from just one direction, but flows from all sides and produces wear on the die from all sides. There is no definite shape to Die Deterioration Doubling, which can take on several different but similar appearances. It often looks like a thin metal shelf or spot which spreads out around something. It can also appear as thick and twisted lettering. There are no crisp lines in a detail affected by DDD, but things look bloated, enlarged, blurry, twisted, and damaged. This is different from Hub Doubling because Hub Doubling appears as a crisp secondary image, rotated minutely from the original. When casually glancing at a coin, the difference is not easy to tell, but when magnified, the difference is obvious on most coins. Another easy way to tell Hub Doubling from Die Deterioration Doubling is the presence of notched serifs. The little flairs on the ends of letters will appear distinctly separated on a Hub Doubled coin, whereas they appear just blurry and washed out with DDD.

Die Deterioration Doubling is extremely common on many coins. Jefferson Nickels and Lincoln cents especially exhibit a large number of affected coins, throughout the entire history of the coin. The 1955 "poorman’s double die" is actually Outside Abraded Die Doubling, and a high percentage of 1999 coins exhibit DDD. Because of the large numbers of coins exhibiting this error, it is not worth more than a few cents over normal value. Yet, Die Deterioration Doubling will always plague the beginning numismatist with the high hopes of discovering a new variety and making a fortune. No more than common wear on a die, Die Deterioration Doubling is a simple error which affects numerous coins.

See also: List of numismatic topics