To get back on the trivia track: even though jade is intimately associated with Chinese culture, there are no notable jade deposits within Chine. None closer than the Amur river at the border.

Jadite, the good looking, colourful stuff, was only introduced in 1748, IIRC, and came primarily from Myanmar (Burma). It first appeared at the Imperial Jade Market in Peking and immediately put nephrite out of the running.