some from weathering
A smooth, black rock is likely to be basalt. Basalt is an extrusive igneous rock that is commonly dark in color and has a fine-grained texture, giving it a smooth appearance.
obsidian
Yes, it is.
Sure, a boulder is a large rock.
Pavement or smooth rock runoff affects waterways because they create more impervious surfaces.
Shale
A rock is a option!
smooth and rough
rough
it can be rough or smooth
It can be both
Metamorphic rock can be coarse grained or fine grained.