On rock tiles you can [[Prospecting|prospect]] for ore, create [[mining|cave entrances]], and terraform it.
Rock tile terraforming with a pickaxe works in the same way as [[digging]] dirt. Stand on the corner you want to ''lower'', activate a pickaxe, right-click a rock tile, and select ''Mining'' (Note: All surrounding tiles must also If you are surfacing you need the four blocks around the tile you are surfacing from to be rockRock as well.). Every few actions you ''lower'' the corner by 1 dirt.
You can not raise a rock tile, but you can raise the corner by dropping [[Pile of dirt|dirt]] or [[heap of sand|sand]] on it.