Nephrite such as Lantian, Shaanxi, were also in great demand). There, white and greenish nephrite jade is found in small quarries and as pebbles and boulders in the rivers flowing from the Kuen-Lun mountain range northward into the Takla-Makan desert area. River jade collection was concentrated in the Yarkand, and the White Jade (Yurungkash) and Black Jade (Karakash) Rivers in Khotan. From the Kingdom of Khotan, on the southern leg of the Silk Road, yearly tribute payments consisting of the most precious white jade were made to the Chinese imperial court and there transformed into "objets d'art" by skilled artisans, as
One of Our Planets Is Missing depart from this galaxy. "One of Our Planets Is Missing" is regarded by some entertainment critics to be "one of the best [shows] that animated [Trek] spin-off has to offer" and "a highly satisfying episode that nicely encapsulates the "Star Trek" philosophy. The show's "animation competently conveys the size and scope of the marauding cloud" which threatens the Federation world of Mantilles. Spock's "mind-meld with the cloud is both logical and satisfying, and Kirk and Spock's wrestling with the need to protect [all] life-forms is intelligent and provocative." Kirk even discusses the rationalisation for his decision "not to kill today"