This masterwork warhammer is made entirely from a extremely lightweight porous white stone. It weighs a mere 1lbs.
However, when exposed to water, it immediately begins to absorb it and increases in weight dramatically. Splashing or raining on the hammer doubles its weight per round of exposure. Submerging the hammer quadruples its weight each round, and clears a 5×5 foot area of water each round. An hour of drying undoes a single doubling increment of weight. The weight of the hammer caps out at 2048lbs, but it can continue to absorb water to a capacity of 1000 cubic feet. This additional absorbtion coninues to affect the length of time required to dry fully.