Jade (Hetian jade) refers to the northern slope of Kunlun Mountain with Hotan as the center, which is produced in Tashkurgan-shache-Hotan-Khotan-Qiemo County 1500 km. It is located in rocks at an altitude of 3,500 to 5,000 meters, and has nine producing areas. Hetian jade can be divided into aquatic products and rocks according to its output. Aquatic products are called seed jade, and mountain products is called mountain jade. According to the different output of Hetian jade, local jade collectors divide it into three types: mountain material, landscape and seed jade. Mountain material is also famous for jade, which refers to the primary mine produced on the mountain. The characteristics of mountain materials are that the pieces are different in size and angular, and the quality is often not as good as that of seed jade. Landscape refers to the jade which is brought to the middle and upper reaches of the river by the weathering and collapse of primary ore. It is characterized by being close to the primary ore, with large block size, slightly rounded edges and corners and smooth surface. Seed jade refers to the jade whose primary ore is denuded by flowing water and transported to the river. It is characterized by small block size, oval shape and smooth surface. The quality of seed jade is generally good because of long-term treatment, washing and sorting. The earliest Hetian jade has been found from Fu Hao's tomb in Yin Ruins. After the Spring and Autumn Period and the Warring States Period, Hetian jade gradually became the main jade talent, and it was not until the Qing Dynasty that it began to mine mountain materials. Dayu, made in Qianlong period of Qing Dynasty, was used to control the water in Yushan Mountain. The sapphire weighed more than 10,700 Jin, which was collected from Maitreya Mountain.

Second, the grade of Hetian jade: Hetian jade can generally be divided into super grade, first grade, second grade, third grade, and there are secondary grades. Special (super) white seed jade is the best in Hetian jade, and it is also the best in Hetian jade in Xinjiang, that is, sheep fat white jade. This kind of jade is extremely rare. In the past, Xinjiang could produce several hundred kilograms of suet jade velvet every year. Although large-scale mechanical mining has been introduced in recent years, the annual output is only a few tens of kilograms, which is on the verge of extinction. Because sheep fat white jade is weathered and transported first, and then washed away by water for thousands of years, the core essence can be condensed. In fact, what is left is very fine, so the color is as white as sheep fat, the luster is as bright as the moon, and the structural components are very pure.

At present, there is no quality grading standard of white jade in China (because the composition, whiteness and delicate structure of jade can be measured, but there is no quantitative index to define oiliness and wettability), which leads to market confusion and some people take the opportunity to fish in troubled waters.

"Sheep fat jade" is only the old name of high-quality white jade in Hotan, Xinjiang (glittering and translucent, oily, but condensed in quality), and also represents the highest grade of soft white jade in Hotan, China, but it has been abused now! No matter what kind of material is white enough, it is called suet white jade, which is irresponsible. According to the present grade (Hoan seed material with tremolite as the main generating substance), only its density, chromaticity, oiliness and purity reach the first grade can it be called' sheep fat grade' white jade. In addition, the real suet-grade white jade is not particularly white, but slightly yellowish! Sheep fat white jade is the best of jade, and the current price is more than 200 thousand yuan a kilogram, far better than gold, and the wearing value is far better than diamonds!

According to China's ancient books, Kunlun Mountain, the birthplace of Hetian jade, is called "Jade Mountain" and "the ancestor of Wanshan Mountain". Money also has the saying that "Jin Sheng Li Shui, jade comes out of Kunlun". Hetian jade in Xinjiang has been developed and utilized for more than 7000 years. As early as the Neolithic Age, the ancestors of Kunlun Mountain discovered Hetian jade and made it into production tools and decorations. Since the Shang Dynasty, Hetian jade has made great strides eastward, becoming the main jade used by the imperial court, and the rulers regard it as a treasure. The Shang Dynasty has developed on a large scale. After Qin Dynasty, it became the main jade material of China jade carving industry, and gradually became the royal jade accompanying the historical process of China. Kings, nobles, and dignitaries throughout the ages regarded Hetian jade as their honorific title and authentic product.

3. Grade identification (identification) standard of Hetian jade: According to the occurrence and color of Hetian jade, the varieties are divided, such as white jade, Bai Yushan jade and sapphire. And the grade is divided according to the color, texture, network, impurities and weight of jade, such as super grade, first grade, second grade and third grade. Grade standards are very important for jade trade. The technological standards of Hetian jade proposed by Xinjiang Yuyuange Industry and Trade Co., Ltd. are listed in the table for reference by relevant parties.

(1) white jade

Super grade: white jade with suet, fine and moist texture, no collateral and no impurities.

Grade I: white in color, fine and moist in texture, and free from impurities.

Grade II: white in color, fine and moist in texture, and free from impurities.

Grade III: white, delicate, moist, slightly broken and free of impurities.

Zero: the color, texture and lump do not meet the above standards.

(2) White jade, aquamarine and mountain materials

Super grade: white or pink, delicate and moist, without collateral and impurities.

Grade I: white or pinkish white, delicate and moist, without broken collaterals and impurities.

Grade II: the color is bluish white or white, the texture is delicate and moist, and there are no broken collaterals and impurities.

Grade III: bluish white or white in color, fine and moist in texture, with slight side branches and no impurities.

Wait a minute. : white or bluish white, with collaterals and impurities.

(3) Jade seeds or mountain materials

Grade I: green color, fine texture, no collateral and no impurities.

Grade II: blue in color, fine in texture, without side branches and impurities.

Grade 3: green, fine texture, slightly twisted, with impurities.