Only the Greyish Bone Chips from the Skeletal Warlord in Karnor's Castle are NO DROP. The rest, Strange Ocre Clay from Army Behemoths in City of Mist, (Black) Yun Shaman Powder off Yun Shaman in Trakanon's Teeth, and I believe the Crushed Dread Diamonds (ground spawn in Timorous Deep) are droppable