Granite

Granite is a type of igneous rock.

Polished granite is the polished version of granite. As with diorite and andesite, it can be crafted from regular granite.

World Generation
Regular granite generates anywhere underground in rich seams, in an identical way to the other two stone types, as well as gravel and underground dirt. It is most commonly exposed to the surface in Extreme Hills biomes but can also be found regularly in other biomes.

Trivia

 * In real life, granite is an igneous rock consisting of quartz, mica and feldspar. Granite has different colors from gray to distinctive pink. The word "granite" comes from the Latin term granum, a grain, in reference to the coarse-grained structure of such a crystalline rock. The pink granite in Minecraft reflected to its real life counterpart that has alkali feldspar in its composition.
 * Along with Andesite and Diorite, Granite is the second block/item to be released in the Pocket Edition before the PC edition (not counting the developmental version). The first is Nether Quartz.