Nephrite is the main source of this gem; it comes in white, red & dark green, which is the most valuable type
Skip to main content ... Nephrite occurs mainly in white and gray, with 
variants in dark green, reddish ... Imperial jade comes mainly from the Hpakan-
Tawmaw jade tract in Kachin ... Rare Red Imperial Topaz ... Gem Silica Sources [DOC] [TLE] JADE main - The Department of Geological Sciences [PAR] Most jade on the market is composed of nephrite; jadeite jade is quite rare and in 
its emerald-green, translucent form is referred to as Imperial Jade or "gem jade".