Cobblestone, or Cobble is present in the game since the first release. It is the material that you get, when you mine a naturally occuring granite. It's most common use is building, since it is very easy to obtain. It can be stacked up to 40 pieces per inventory slot. Currently it does not naturally occur in maps. It has the same durability as smooth stone (granite).
In crafting, it is used to make stone bricks. Four cobblestones are needed to complete the recipe, however, you get four stone bricks, so practically every cobblestone worths one stone brick block. Their main use is for making stone tools. Stone tools are the second strongest tier of tools currently implemented. They are stronger than wooden tools, but weaker than iron tools.
|Wooden Pickaxe||2.5 secs|
|Stone Pickaxe||1.66 secs|
|Iron Pickaxe||1.25 secs|
Cobblestone Is Used To Craft Gravestones, Tools, Stonebricks, etc.