Mint Mark Madness

[Tuebits]

Take a look at this 1982 5 Cent Mint Mark. It seems to have issues. What do you think?

Tuebits

[diamond]

This is a case of "flat field doubling". In other words, you've got imperfectly aligned proof strikes.

You'll find more information here:

http://www.coinworld.com/articles/viewarticle/imperfectly-aligned-proof-strikes-produce-fla

[Tuebits]

Thanks, the article described this coin to the "T".

Tuebits

[wavysteps]

Thanks Mike.

[Tuebits]

I'm thinking the doubling on this torch is also flat field doubling.

[Tuebits]

1973 proof cent with flat field doubling

Attached are photos of a 1973 proof cent. The word "LIBERTY" seems to have flat field doubling.

Tuebits

[Tuebits]

Here are a couple of pictures of a 1968 S Cent with flat field doubling of the date and mint mark.

Tuebits

[Tuebits]

Here are some photos of a 1969S cent where Liberty has flat field doubling.

Tuebits

[Matthew]

Flat field doubling is a bit different than machine doubling. Here is a page describing the characteristics of Flat Field Doubling and here is a page describing the characteristics of Machine Doubling.

The first images of the mint mark, as Mike identified, is Flat Field Doubling whereas the following images of the reverse and of various coins are Machine Doubling.

[Tuebits]

Thanks for the clarification.

Tuebits

[Merlin8971]

I'm a bit confused

You mentioned in the article that "the die assembly pivoted around an axis located well to one side of the die’s central axis." I was wondering how another axis could be involved.

With the nickel and only three characters being affected, would this also be a result of an out of alignment (tilting) of the hammer die?

This is somethign that I find curious about machine doubling. I cannot figure out how some characters show strong shelf doubling and characters right beside the doubled character do not show any doubling. I have seen Washington quarters with In God We Trust doubled to the left and the Mntmark doubled to the left.

[Tuebits]

68 Quarter Question

Matthew, I'm looking over this 68 Quarter, and see it has machine doubling on the mint mark. However, I think there is some Flat field doubling to the north of the primary mm. Photos attached.

Tuebits