Some basic rocks
Stone is the first of the basic building blocks. It's normally found near the surface and goes deep underground. It's by far the most common block, and produces cobblestone if mined with a wooden pickaxe or better. It sometimes has gold, iron or coal deposits in it underground, and diamond deposits can also be found in the indev and infdev versions. New blocks can be crafted by smelting cobblestone in a furnace. It is not affected by gravity.
Crafting
Stone is used a few crafting recipes: Buttons, and Stone Pressure Plates.