Is this gunk or corrosion under a 16570 bezel?

Posts
90
Likes
159
Advertised as unpolished, so wondering if it's just dirty. Thoughts? Trusted seller, just haven't seen this before.

 
Posts
15,643
Likes
46,678
Likely dirt! One way to find out is to have the bezel lifted, and grunge removed. Or clean it best possible, then don’t worry about it.