Sandstone

Sand and gravel clumps into sandstone at your touch.

You can transform into sandstone one 5–foot block of sand or gravel per level. This spell allows you to reinforce ditches made in sand, building makeshift walls.

Sandstone does not have the resilience of normal stone: It has a hardness of 6 and only 10 hit points per inch of thickness. A 1–foot–thick wall of sandstone created by this spell has hardness 5, 25 hit points, and a break DC of 30. Sandstone is useless for the purpose of making weapons.