VancouverIslandCoinKid had the right idea to try and scratch it off. Thank you.
I turned the coin on its side and looked at the "dot" with my loupe rather than my USB microscope (which I used to take a picture) and low and behold it is not a raised dot but a circular dent in the field -- consequently it is just
PMD.
Hopefully I've learned a lesson here to double check before posting.
Sorry for wasting your time. I guess I should just stick to looking for die cracks...