Minecraft wiki entry for Advancement_guide, associated text: To get the actual advancement, you must find stone (which is easy, you don't need to find a cave for this), and mine it with your wooden pickaxe to get cobblestone (stone will become cobblestone if you mine it without a silk touch pickaxe). Exposed stone can be found on the sides of hills and in ravines/caves. If you find a cave or ravine, do not go deep into it, because you will encounter mobs (such as zombies and skeletons).