1925 S Penny Struck Through A Late Stage Die Cap?

I think the obverse was just struck from a very worn die, common for branch mint issues of this era.

How can you tell the difference of a struck through late stage die cap and a Struck Through Grease error? Error-Ref has an example of LMC pennies struck through a late stage die cap and it looks similar to the one I have: http://www.error-ref.com/struck_thr...age_die_cap/

I'm trying to get better at recognizing the differences between errors.

The easiest way to tell the difference is to look at the inside of the rims, where the design/fields and the rim meet. On a coin struck with a Grease Filled Die the rims will always be fully struck.

On a die cap, not so much. The die cap covers part or all of the sharp edges of the die, producing a more flattened, rounded rim junction and also tends to affect the rim unevenly, depending on exactly how the cap is sitting on the die.

When grease is involved the rim will be unaffected.

Notice the three examples in the link you provided all have some portion of the obverse rim showing weakness (partially) while the reverse rims are clean and unaffected?

HGK3 thank you so much for providing that information! It's a really helpful diagnostic I'll use moving forward. I do have a follow-up question. Do all STDCs exhibit that issue with the rim? The 1987 penny referenced on this page seems to have a fairly well formed rim: http://www.error-ref.com/capped-die...ling-raised/

In addition, when scoping the rim on my coin a bit closer I noticed what I initially thought was a crack is actually raised. It looks almost like finning but I've never seen finning on a coin exhibited that far away from the rim.

What could cause something like this?

@crh, that circumferential raised region looks like Ridge Ring, another indication of this coin having been struck from a tired die.