Netherrack

Bloodstone (aka Hellstone, Netherstone, Red Mossy Cobblestone, Brimstone) is a stone that is found only in the The Nether. It burns indefinitely, so it is a good way to have everlasting light. It also has an extremely low resistance to TNT. The dark red of the stone, along with its abundance in The Nether give it a very chilling ambiance, and also make the region seem darker than it is.

It is possible that the official name of this stone may be Netherstone. (Unconfirmed)