Cylinder Challenge (Without Reference)

I first found the cylinder challenge on 4chan's art board /ic/. In this challenge, you are to evaluate your painting skills by painting different textures. You aren't supposed to use texture brushes or texture overlays for this challenge. It's just you, your tablet, and your anti-aliased brush, transparency and the color sampling tool.

I'm doing a before and after. The before is what I know now and the after is what I see from references.

I've collected a few semi-finished cylinder challenges and took clues and ideas from them.

A misconception people started to get was that they could just paint a plank of wood or a pile of leaves instead of using the cylinder but you're supposed to make the cylinder have the texture, not show that you can draw objects.

Done. I'm not gonna attempt the raw gemstone.