Terracotta

Hardened Clay is a block with a blast resistance comparable to that of stone-based blocks.

World Generation
Hardened clay can be found naturally in mesa biomes. This yields a large quantity of hardened clay.

Usage
Hardened clay has the same blast resistance as most other stone blocks, which is significantly higher than the block of clay before being smelted. A block of hardened clay when one meter away from an explosion will protect any blocks behind it, though it will be destroyed in the process.