1997 No Mint Mark Double Die

What you see here is what is called Die Deterioration Doubling or DDD. The classic signs of this is the apparent smearing of the devices towards the rim around the coin.

I lean toward DDD.



to the CCF!

But note, this always shows on the direction towards the closest rim.

That is how you can tell it is die wear. The planchets are smaller than the normal cent. During the strike it get shaped in a collar that allows the outside edge to be determined. This movement of the metal, hundreds of thousands of times, creates wear on the dies. That is what you are seeing. The single squeeze dies wear in the same direction, but the fields are what is affected first on the Zincolns.


Note the Ridge Ring is appearing on the reverse also.
On the older style dies the devices were affected, not the fields.

Note the devices move on the older style dies. But it gets even worse:

Possibly if you looked on the reverse, you will see the same thing on the tops/bottoms of the devices closest to the rims. Just normal die wear.

Why does it happen this way?
My guess would be the difference in height of the designs. The single squeeze dies have a lower profile. On the only dies, they are higher profile devices. So that is why I feel it changes with die wear because of the difference of the profiles of the devices.

CoopHome: Why do dies show die wear? because of the higher numbers of struck coins, that go through the same repeated procedure over and over.