What is Pounamu / Greenstone / Nephrite Jade?
Jade is a name used for two distinct materials, the less common and more valuable “Jadeite” with a glassy or pearly luster, and the more common nephrite, with a silky luster. Jadeite is sodium aluminium silicate, and varies in colour through white, apple green, emerald and brown. Nephrite is calcium and iron magnesium silicate, and is a transparent to opaque (translucent in thin slices) mottled-green colour with dark inclusions, consisting of interwoven, long, thin fibers. Nephrite is readily available in New Zealand, and is used by craftspeople to make tools, ornaments, and ceremonial objects of Maori design. This note was prepared with the help of information from the Academic American Encyclopædia, and the gem collection of the Carnegie Museum of Natural History in Pittsburgh.