Khotan, also rendered Hotan, is an oasis city in the southern Tarim Basin of Xinjiang Uyghur Autonomous Region, in north-western China. It is the historical source of the highest grade of nephrite jade traded into China, supplied to the imperial workshops from at least the Bronze Age and continuously from the Han dynasty onwards. The river-cobble nephrite from the Khotan region remains the standard against which other nephrites are judged in the Chinese trade.

Geological and geographical context

Nephrite at Khotan occurs in two main forms. Mountain jade, called shan liao, is mined from primary deposits in the Kunlun Mountains south of the city, where serpentinised ultramafic rocks have produced nephrite veins. River jade, called zi liao or seed jade, is recovered from the cobbled beds of the Yurungkash and Karakash rivers, the White Jade River and the Black Jade River respectively, which drain the Kunlun range and run through the Khotan oasis. The river cobbles have been tumbled and rounded by long transport, producing the rounded forms that the trade prizes.

Quality and varieties

The most valuable Khotan nephrite is yang zhi yu, mutton fat jade, a translucent white nephrite with a fine even texture and a slightly oily lustre that the trade compares to mutton fat. Other recognised varieties include sugar jade, with brown or russet patches; black jade; and various greens. Quality grading depends on colour purity, translucence, fineness of texture, and absence of cracks. River-pebble Khotan jade with a natural skin of brown or yellow oxidation is particularly sought after, since the skin can be incorporated into the carving as a decorative element.

Historical use

Khotan nephrite supplied the Han, Tang, Song, Yuan, Ming, and Qing dynasties, with imperial workshops in Beijing producing carvings of extraordinary refinement. The Qianlong emperor, ruling from 1735 to 1796, was particularly devoted to jade and reorganised the imperial supply from Khotan. Major museum collections including the Palace Museum in Beijing, the National Palace Museum in Taipei, and the Victoria and Albert Museum in London hold Khotan-jade carvings that document the tradition.

Modern production and supply

The traditional river-pebble supply has been heavily worked over centuries and high-grade material is increasingly scarce. Modern production includes both mountain mining and river prospecting, with restrictions imposed by Chinese authorities to manage the limited resource. Xinjiang's regional government has imposed permit systems and seasonal restrictions on river prospecting. The shortage has driven prices for top-grade Khotan nephrite to extraordinary levels, with mutton-fat material trading at prices comparable to high-grade jadeite.

Distinction from jadeite

Khotan jade is nephrite, a calcium-magnesium-iron silicate, distinct from the jadeite that dominates the modern Chinese jade trade. Jadeite became prominent in China only from the eighteenth century onwards, sourced principally from Burma. Most pre-Qing Chinese jade carvings are nephrite, much of it from Khotan, and the cultural prestige of Khotan jade in the Chinese tradition is rooted in this long historical association. Modern Chinese collectors often distinguish carefully between gao gu, the older nephrite tradition, and contemporary jadeite work.

Significance

For the trade Khotan jade is the prototype of the Chinese jade ideal: white, translucent, finely textured, often river-tumbled, and integrated into a thousands-year-old tradition of imperial carving. Anyone serious about jade history begins with Khotan and works outward from it.