Moly(?) coating on filter end caps

[OVERKILL]

I wiped off the end caps on the Jeep filter today because I didn't have gloves and didn't want to get oil on my hands and I noticed a dark coloured coating that appeared to wipe off the surface (this wasn't apparent until the wiping was done).

I have 4x filters (all OG FRAM Ultra/Titanium XG2/FS2's) here, off two different vehicles (running variations of effectively the same oil), which I performed the same action on, and they all exhibit this same trait. Furthermore, if you let the filter sit, more of this migrates onto the surface, which would lead one to logically conclude that this is part of the oil film.

I'm assuming this is moly. It's non-ferrous, but that's about as far as I've gotten with testing it. I don't have a microscope, so I can't see if it's visible in that respect.

Has anyone else noticed this with high moly lubes and filters with metal end caps?

 

[fantastic]

Never, That's a new one but I can't recall high moly oils I've used.

 

[DCDG]

sludge in disguise.

 

[ZeeOSix]

(running variations of effectively the same oil)

What oil?

 

[OVERKILL]

What oil?

HPL Super Car 0W-40 and 0W-20 (identical additive package).

 

[ZeeOSix]

HPL Super Car 0W-40 and 0W-20 (identical additive package).

Maybe it's suspended particulate from cleaning of the HPL that's filtered out and stays in the those high efficiency filters.