Terracotta

Hardened clay is a block with a blast resistance comparable to that of stone-based blocks. It is useful in that you can create colorful buildings without resorting wool, which is flammable and has a low blast resistance. It serves no purpose but a decoration or a protection-like material (relative that it has a blast resistance that's the same as stone). It can be obtained by smelting clay blocks.

Stained clay (also known as stained hardened clay) are coloured variations hardened clay. They are available in the same 16 colors as wool, although the colour is more dull.

Behavior
Hardened clay has an above-average resistance towards explosions. Unlike normal clay, a wall of 4 hardened clay blocks thick can withstand a direct TNT or creeper explosion while only one column would be destroyed.

Hardened clay can be colored with dyes to create stained hardened clay for decorations or builds. All colors of hardened clay are currently available.

Trivia

 * Hardened clay was suggested by BlameTC.
 * Stained Clay has the same blast resistance as ordinary hardened clay.
 * Hardened Clay placed against TNT will protect any block behind it from the explosion, but will be destroyed in the process.
 * There is no actual blue hardened clay. Dyeing it blue or teal will create a purplish color.