found: Work cat.: Montgomery, P. Utility of jade in pre-contact Alaska, 1999:t.p. (among gems, jasper, obsidian, ivory and jade were used by Alaska Natives for utilitarian purposes; of these, jade was the first choice for work that required the most durable tool or weapon; nephrite's toughness made it ideal as a material for tools and weapons) p. 3 (jade implements; celts and axes of nephrite or other hard stone; Alaska Natives worked raw jade into implements; jade tools; jade tools and weapons; among stone tools, those made of jade were the most important)
