How to differentiate between acid damage and struck through grease?

So I have a coin that is assuredly damaged from something, but I realized that I don’t have the best knowledge on differentiating acid damage and through grease strikes.

My assumptions are that grease would not leave layers or shelves, but instead a sort of smooth depression that increases towards the center of the grease pool.

Also, I assume that the coin struck through grease would not have significant color changes whereas acid would change the surface color where it interacted.

Lastly, the reverse of a through grease should be more sharp/detailed compared to a regular strike.

What are some other indicators between the two?

 

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I see the orange peel effect and MD, so it's just a guess that the obverse die was in a late stage of deterioration. But I would prefer to defer to @paddyman98 and @Fred Weinberg on this one.

 

I was thinking Die Deterioration.. But so much? Nice 1971, my Birth year

 

I don't see it as either. "Grease" would be assumed to reduce the height of 'TR' in trust where the damage seems to pass, and acid doesn't usually cause plateaus or different depths on a coin without corroded areas. Since this was the first year with the non-silver composition, it could be associated with the mix? Jim

 

Well now I'm more confused than I was before. I wasn't settled on it being acid, but damage always makes the most sense... there's definitely a lot of die deterioration, which could explain a lot of the effects, but the off color is what has me thinking there's more to it than that. Hopefully Fred will have a chance to look at it and chime in. Thank you everyone for your input.

 

Curious about the flaring at the ear and extended ear lobe.

 

It sure does stick out. I'll try to get better photos tomorrow. Off to bed soon!

 

Alfred E Neuman variety ?

 

It's stained, after it was in circulation.

Not an error, imo.

It has a typical strike for that date -
as mentioned, worn/overused dies.

All the discoloration you see is PMD

 

Well, I always thought it was PMD. What do you think causes the steps/shelving/raised areas in there?
I think I’ll dip it in acetone and see if the color goes away.

 

Worn die for me. I have at least one saved but I’m in Florida till April so no pic. Acetone bath can’t hurt