Could be pumice or scoria.
It is a very light baked texture but you can say that it is rough but not hard.
hard and rough
soft, quite light yet a bit rough and crumby
The difference between rough and smooth is the texture. Rough things have a bumpy, abrasive texture. Smooth things have are not rough.
The options for the question are:Smooth texture and light colorSmooth texture and dark colorRough texture and light colorRough texture and dark colorThe correct answer would be rough texture and dark color (4).
The difference between rough and smooth is the texture. Rough things have a bumpy, abrasive texture. Smooth things have are not rough.
Pumice is a volcanic rock that is so full of gas bubbles that is it very light, and rough surfaced.
rough
rough
rough
rough
The rock had a scratchy, rough texture.