Nether Bricks

Nether Brick is a type of block that will be added to The Nether; they first appeared in the first 1.9 Pre-Release. They are used to form generated structures in The Nether, making up a majority of Nether fortresses, forming their walls and supporting pillars. Currently, the player can not craft Nether Brick. However, Nether Brick can be crafted into Nether Brick Stairs and Nether Brick Fences. Nether Bricks take approximately five seconds to mine with a stone pickaxe, which is much longer than the time required to mine normal stone. Nether Bricks do not stay lit on fire, unlike Netherrack.

Trivia

 * Despite common misconception, Nether Bricks cannot be made out of Netherrack.
 * Possibly a bug, new Nether Bricks will sometimes be created by placing Netherrack adjacent to existing Nether Brick.
 * Redstone can be placed on Nether Brick as of 1.9 pre-release 4