gems, jade, jadeite, fei cui, Mesoamerica, Mexico, Guatemala, Costa Rica, Mayans, Olmecs, Aztecs, archaeology, history, archaeogemology, China, New Zealand

Jade, regarded as a material used for prehistoric tools and works of art, presents numerous aspects of interest. The distinctive properties of nephrite and jadeite, which are responsible for their characteristic appearance and hardness, may be used to distinguish them from one another and from other minerals. The occurrence of jade in relatively few localities throughout the world, together with the relationship between these localities and the regions in which jade was worked, raises important questions. Finally, the study of the history of jade working reveals evidence of considerable technical skill, even during very early periods.