|
The term jade
is used for two different rocks made up of different silicate minerals. Nephrite
jade is composed of amphibole mineral actinolite. Jadeitite consists almost
entirely of jadeite. Nephrite and jadeitite were used by people from ancient
times for similar purposes. Both are about the same hardness as quartz, and
they are exceptionally tough. They are beautifully colored and can be delicately
shaped. Thus it was not until the 19th century that it was determined that "jade"
was in fact two different materials. Jadeitite is rarer, found in fewer than
a dozen places worldwide. Translucent emerald-green jadeitite is the most valued.
Jade is the official gemstone of British Columbia, Alaska, and
Wyoming.
|