Nephrite is the main source of this gem; it comes in white, red & dark green, which is the most valuable type
... Beside red, black, yellow and white, spinels also occur as green 
stones... [DOC] [TLE] Nephrite Jade Gemstone Information - GemSelect [PAR] Feb 28, 2014 ... Today, green nephrite is considered to be the most valuable nephrite, but ... One 
of the most important sources for fine nephrite jade is New ... but it can also occur 
white to gray, yellowish to brownish, near-black and other colors.