Voidstone

Voidstone is a rare, magical rock that destroys anything that comes in contact with it, with the exception of other pieces of voidstone and, presumably, certain powers of religious or magical base. It is first seen in Lisa Smedman’s second part to the Lady Penitent trilogy, Storm of the Dead. It is unknown where to obtain such material. It is mentioned by Q'arlynd Melarn that voidstone is a solidified piece of the negative material plane.