* Hardness: This refers to a material's resistance to scratching. Diamonds are the hardest natural material known, so they'd be considered the "roughest" in this sense.
* Texture: A stone with a very uneven surface, lots of bumps and protrusions, would be considered rough in terms of texture. This is subjective and can vary greatly between stones.
* Abrasiveness: Some stones, like pumice, are very abrasive and good for polishing or cleaning due to their rough texture and composition.
So, to answer your question accurately, we need more context!
* What do you mean by "rough" - hardness, texture, abrasiveness?
* What is the context? Are you talking about stones used in construction, jewelry, or something else?
Once you clarify, I can give you a more precise answer.
