User:Baalsexy/Khotan Jade

Khotan Jade, also known as Hetian jade, the ancient name Kunlun jade, by ancient Kingdom of Khotan,(now Hotan, Xinjiang, China), is a famous Nephrite variety, Have of history more than a thousand years.

History
Formerly 21th century,people believed that Zhang Qian, the messenger of the Emperor (Han), discovered and offered it.But the archaeological results prove that the introduction of the Khotan Jade into China was earlier, and Khotan Jade was discovered at the Yangshao culture Site 7,000 years ago.

Ingredient
Khotan Jade is a kind of nephrite, whose main component is the Tremolite(a member of the amphibole group).And if the higher the content of tremolite, the better the quality.

Physical properties
The mohs hardness of Khotan jade is 6.25 is more harder than Orthoclase but softer than Quartz..The refractive index of khotan jade is 1.610, and the specific gravity is 2.95.

Surface distribution
Narrow sense of Khotan Jade is nephrite that only produced in Hotan County, Xinjian, Qiemo County of Bayingolin Mongol Autonomous Prefecture. Khotan Jade is distributed in the Kunlun Mountains in the south of the Tarim Basin.

But beginning in February 2018,Guobiao standards that China government released that Khotan Jade does not have the meaning of origin, so nephrite whose main component is tremolite, which is  produced by Qinghai, Russia, South Korea, Canada or other areas can also be called "Khotan Jade"