Shatterstick

A shatterstick is a nonmagical, 12-inch-long, 4-pound stake made of blue-tinged infernal iron mined on Cania, the eighth layer of the Nine Hells. When embedded in earth or pounded into solid rock, the stake emits a seismic vibration in a 20-foot radius centered on itself for 1 minute, shaking the ground in that area for the duration. When the effects ends, the shatterstick breaks apart, becoming useless, and all structures within 20 feet of it take 35 (10d6) bludgeoning damage.