Grey Sandstone Cobbles are usually bricks with a rectangular shape and rough-hewn edges. cobblestone and stone bricks both have a blast resistance of 30, so the only reason to spend coal on smelting cobblestone for the building is for aesthetics. In order to reduce creeper damage, it would be advantageous to build homes out of stone bricks rather than cobblestone if they had a better blast resistance. Grey Sandstone Cobbles blast resistance could be lowered, while stone bricks stay at 30.