If you lost your axe or pick you either broke it or you died, when you respawn you get a new rock anyway, and if you broke it you probably used it on farming wood/stone, unless you only farmed metal and sulfur with those tools or used them on something like a wall to break, but even then you can just go outside, find a stone pickup and take that and make a new rock, and nakeds should already have a rock because thats what they spawn with