Bricks

Brick is a decorative building block that does not naturally spawn anywhere. It is mostly used to make nice looking homes and towers. Since brick is non-flammable, it is often used to make fireplaces. Brick resists explosions no better than cobblestone. A pickaxe must be used to recover the resource of a placed block, but it will take under a second to break. Breaking a block with the player's hand is slow and will not yield the resource.

Current uses of Clay are to be smelted into bricks or the new (as of 13w17a) Hardened Clay block. Each clay block yields 4 clay balls, which are smelted into individual bricks, which in turn are crafted into brick blocks. For each clay block found in a map, players can make 1 brick block.

History
Fun Fact: Clay was first even more rare than diamond. When 1.7.3 had come out they increased the spawn rate.