Fish Gills On Liberty's Neck, Possible Unlisted 1921 Peace Dollar VAM?

Hi everyone,

I was hoping some of the VAM experts here could help me identify a die marker or possible die variety on two of my Peace dollars.

Both coins show what appears to be the exact same unusual marking on the front of Liberty's neck/throat, almost making it look like she has "fish gills." I've labeled the two coins "Strong" and "Weak" based on how clearly the marking is visible. On the Strong example, you can clearly see that the marking is raised above the surface of the neck, which makes me believe this is a die-made feature rather than post-mint damage. I included several photos, although I apologize that a few of the microscope shots are slightly blurry because the microscope moved while I was zoomed in.

The fact that I've found what appears to be the same feature on two separate coins makes me pretty certain it is a die artifact and and potentially something that appears on dozens or hundreds of other examples. However, I haven't been able to find a matching variety. I went through the 1921 Peace dollar VAMs on VAMWorld and haven't found anything that seems to match this feature. Most of the VAM markers I've come across seem to be relatively fine, hairline die-polish marks, whereas these are fairly obvious markings that can easily be seen with the naked eye.

I'm also curious what could have caused it. One possibility I wondered about is a die clash involving the reverse rays, but I'm having trouble seeing how a clash could produce something localized entirely within the deepest area of the obverse die while leaving the surrounding fields clean. The reverse also doesn't appear to show any obvious abnormalities.

Another possibility I came across is that a foreign object or piece of debris was struck into the die. That seems like it could potentially explain both the raised nature of the marking and why it is localized to one small area of the coin, rather than affecting the surrounding fields.

I'm relatively new to coin collecting, so I may be completely misunderstanding how these things occur and apologize if this post doesn't belong in the VAM subcategory. I'm driving myself nuts trying to find another example or an explanation for it!


Thanks in advance!