1. Observing the internal structure from the side light:

First, choose a plane to observe, and try to choose a bigger one. For example, when observing jade cards, the front is usually chosen as the observation surface, and when the light enters from the side at a 45-degree angle, the observation surface is larger.

When operating, pay attention to the need to cover the light of the flashlight with your hands to avoid strong light, and at the same time avoid high-edge light, so that we can clearly see the internal structure of Hetian jade on the observation surface.

2, hetian jade crack observation:

If you use a flashlight to observe the impurities and flaws in jade, you should stick the light source close to the back of Hetian jade and constantly translate the light source of the flashlight on the surface. If there is dark or uneven refracted light, it means that Hetian jade has cracks. If not, it means that Hetian jade has no cracks.

3. Judging the fineness of jade by texture:

By observing the cloud-like texture structure, it is easier to judge the fineness of Hetian jade. We can set four standards for cloud floc texture: thickness, length, uniformity and shade.

Radish grains are fine, short, uniform and hidden, but thick, long and uneven, with obvious differences.

Extended data:

When Qin Shihuang unified China, Hetian jade was called "the jade of Kunshan" because it was produced in Kunlun Mountain, and later it was called "the jade of Khotan" because it was located in Khotan. It was not until the establishment of Hotan Zhili Prefecture in the ninth year of Guangxu in Qing Dynasty (1883) that it was officially named "Hotan Jade". ?

Hetian jade's famous product is the national treasure of the Western Han Dynasty-Queen's Seal, which is collected in Shaanxi History Museum. Its texture is Xinjiang Hotan sheep fat jade. So far, it is the only seal of the Empress of the Han Dynasty and the first batch of cultural relics forbidden to go abroad? . The emblem of the 2008 Beijing Olympic Games "China Seal" is also made of Hetian jade in Xinjiang. ?

Hetian jade is a metamorphic rock formed by the contact between magnesium marble and intermediate-acid magmatic rocks, which contains tremolite, hornblende, actinolite and other mineral aggregates. Its chemical composition is hydrated calcium magnesium silicate, the chemical formula is Ca2(Mg, Fe2+)5[Si8O22](OH)2, the density is 2.95-3. 17, and the Mohs hardness is 6.

For a long time, there has been a great controversy in academic circles about whether Hetian jade is divided by origin or mineral composition.

20 13, 12, 17 and 20 14, 13 China National Standards Management Committee and National Standard Samples Technical Committee approved the release of national standards GSB16-3061-

People's Daily Online-Hetian jade sample "national standard" will be issued.