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
Ornamental turning intervals around the work (so producing grooves or bumps on the surface) to non-circular movements whereby the whole of the circular shape is removed to give a completely different form. Such shapes are achieved by various means, the principal ones being: Ornamental turning is believed to have originated in Bavaria in the latter part of the 15th century when it consisted mostly of rose-work, being done by using a cam or template (called a rosette) mounted on the lathe spindle and allowing the headstock to rock under tension of a spring or weight, to follow the contour on the edge