Causes
Annealing Errors
During the annealing process ofOveruse of Dies
In modern presses, a die strikes approximately 120 coins a minute. This is a large number of coins produced in a short time, and obviously the die cannot last forever. However, the process of wearing the die is only hastened by the metals used in coins.Identification
Die deterioration doubling is a result of a few simple causes, but it can be difficult to positively identify. There are a number of different features which appear similar, but the characteristic traits of each are easy to identify with practice. Die deterioration doubling is often mistaken for hub doubling. The causes of the two types of 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 it occurs in other features, like an image of aTypes of die deterioration doubling
There really are two different kinds of DDD: Inside and Outside Abraded Die Doubling. This is because Die Deterioration Doubling manifests itself in two different ways. The two classes look different, and are caused by wear in two different places. Inside Abraded Die Doubling is caused by wear around the edges and inside the actual detail affected. It appears as an enlarged, irregular outline of the element overlapping the original design element. Outside Abraded Die Doubling is caused by actual wear in the field of the die. The field of a die is the highest point, so when a mint technician polishes the die or the metal flow of a coin wears it away, the field is the first thing to be worn down. The difference here is that Outside doubling does not overlap any of the original design, but rather appears like an irregular shelf around the object.Numismatic Interest
Many beginningSee also
*External links