/ic/ - Artwork/Critique

The first problem is more suited for /v/, but I think that starting an entirely new thread for these questions are a little unecessary.

I'm drawing this man. One problem: I have no idea what he's wearing in pic related.
If it's a necklace, then it really is the most strangest necklace I have ever seen on a character. The only other theory I have is the filename.

My second issue regards values. I'm terrible with colours, so all my drawings are in black/grey.
This character has sleep-deprived bags under his eyes, and it feels hard to convey this with a B pencil without making it look as if I'm /just/ going to town with the shading underneath the eyes. Does anyone have some sort of guide or reference for this specific problem? Or will people understand that the large dark areas that stretch beyond the eyes are actually from sleep deprivation; am I fretting over nothing?