1968D with sunken face

[VAB2013]

I think I have asked this question before, or I was going to. Cannot find anything from searching the forum or glossary. Please tell me again what causes this. It just doesn't seem like it was attacked by verdigris. Thank you.

[Roller]

I would like to see more of the area under the ear. Have you looked in errorref.com under die subsidence?

[VAB2013]

Thank you Roller. Here is under the ear. I have looked at error-ref.com several times but that is all way over my head.

[jfines69]

To me it appears to be heavy dirt/contamination on the coins surface and some one tried cleaning it off... There may be some metal loss from environmental corrosion but other than that it appears normal... The darkened areas stand out more with the lighter tone of the rest of the coin... Optical illusion???