Thank you, folks!
Yeah, as I look at it, the hand is resting on the fold and not actually gripping it. I need to show the cloth between the thumbs. I'll finagle with that.
Metal, I totally see that. Earlier when I colored, I think I had more metal in mind. I played around with the idea of changing the green to a rust color (rusted iron), or keeping the green and changing the greys to a copper color (tarnished bronze), but then I felt the placement of the eroding color would look too directional and not organic. Consequently, I turned around and said, "It's no longer metal; now it's stone." I see now that someone picked up on that too in the contrast. I'm still gunning for stone though, as I need to learn!
I'll cut back on the shadows and try a more neutral/warmer green. Smooth out some lines, etc. Might mess around with different colors in another mock-up to compare what I can do about this palette. I'll share it in my next post!