Stone

Stone (AKA Smooth Stone) is a naturally occuring block that, when mined, drops Cobblestone. Stone is found underground in great numbers; it can also be found on the borders of lava pools. It is obtainable by smelting Cobblestone in a furnace.

Crafting
Stone can be used to craft Stone brick, Stone slabs, and other stone-related items. It is also used to make some Redstone related items  like Redstone Comparator or Repeater which will be added in 1.0.0.

Trivia

 * In 0.9.0, Polished Andesite, Diorite, or Granite can be used in the stonecutter with the same crafting as stone items. (Example: 3 Polished Andesite can craft Stone slabs)
 * Stone is renewable as cobblestone is renewable.