Variscite

Variscite, also known as lucinite and peganite, was an ornamental stone found in nodules or in rock seams.

Description
This stone was translucent and came in deep to pale shades of yellowish green. When cut cabochon and polished they occasionally displayed gray and yellow bands or rings ("eyes"). A typical stone had a base value of 10 gp.

Powers
Variscite was poisonous to lycanthropes and, if delivered into the bloodstream on the tip of a weapon, caused triple the normal damage for that strike. Once a lycanthrope was infected with variscite, further exposure did no additional harm until the subject recovered&mdash;a process that took a full 24 hours. Infection could also be accomplished if a variscite stone, say mounted in a ring or other jewelry, were pressed into an open wound on a lycanthrope, or touched to the creature's tongue.