A carved imperial jade dragon vase from the National Gem Collection. Imperial jade is the finest quality of jade and is one of the world's most valuable gems, particularly in Asia. Imperial jade is known for it's near-transparent quality. It is called imperial jade because in imperial China, the finest quality jade was reserved strictly for the royal courts. Jade comes in variety of colors as shown by this vase, which exhibits very light-to-medium green and light purple colors.