Stone

Stone is an item added by the Realism Survival mod. It is crucial for the first tools.

Uses
Stones can be thrown at mobs to damage them, or they can be thrown on the ground to get a flint (a small percentage). If you throw it on a wood block, it has a chance to catch fire.

How to get one?
Stones will spawn around in your world and if you destroy them (or pick them up), with your hand, they'll drop a stone.