The obsidian amulet is an item used only in the Creature of Fenkenstrain quest, although it can be obtained after the quest. It is found upstairs in Fenkenstrain's Castle. There is a bookcase in the east room. The player should search it for the Handy Maggot Avoidance Techniques book, and he/she will also find the amulet. The Obsidian amulet forms a star amulet when used with the marble amulet.