Xinjiang has a long history of producing precious stones and jade, and is known as the "hometown of precious stones and jade". Hotan jade, also known as "Kunshan Jade", has been famous since ancient times, enjoying a good reputation both at home and abroad, and is very popular in the gemstone market. However, deep in the Tianshan Mountains of Manasi County in northern Xinjiang, there is another type of jade called "Tianshan Biyu" or "Manasi Biyu".
"Biyu" is a variety of nephrite (Hotan jade), which means "green jade". The characteristics of Biyu are that its texture ranges from bright green to dark green, and black spots are often present in the jade (due to impurities such as magnetite and chromium spinel). The most valuable Biyu is the one with a color ranging from bluish-green to bright green, while those with black impurities and lighter colors are of secondary value.