Observe the surface of jade

Hetian jade has a smooth and shiny surface, and most Hetian jade will be washed because of handling, and there will be cracks and pits of different sizes. At the crack, there is usually a sugar peel produced by oxidation. Fake hetian jade has low gloss and is not really so smooth.

Observe the luster of jade

Hetian jade rotates in the sun, without large grinding surface and grinding trace, and its luster has not changed. The surface of fake hetian jade is polished and linear. Gloss will also change during rotation.

Observe the body

True and false Hetian jade pulp is also different. The fake hetian jade skin and flesh are completely separated, and there is no transition color. If you really look at the cross section, the meat next to the skin will have a little transitional color. Really, the pores and skin color of Hetian jade extend into the meat next to the skin like small nails.

Observe cracks

Observing cracks can also distinguish between true and false. More than 90% of Hetian jade will have cracks of different sizes. The color of cracks is dark, which is a gradual transition color of nearby colors. The color of the fake crack is not much different from that in the vicinity, like a net. The crack of artificial polishing material is Qin-colored line, which is heavy outside and light inside, but the opposite is true for seed material.

Extended data

Hetian jade is one of the "Four Famous Jade in China" (the third place is lantian jade in Shaanxi, Xiuyu in Liaoning and dushan jade in Henan). The traditional narrow category refers to the jade produced in Hotan area of Xinjiang, which is famous for its "inferior material". Hetian jade in a broad sense refers to nephrite (real jade). Although Hetian jade is named after Hetian, Xinjiang, it is not a regional concept in itself, nor does it refer to the jade produced in Hetian, Xinjiang, but the name of a class of products. China named all the stones with tremolite accounting for more than 98% as Hetian jade, which are within the national standards.

Jade characteristics

Quality of materials

Texture is a comprehensive expression of jade, including shape, moisture, cracks, impurities and so on. The mineral composition of Hetian jade determines its excellent texture:

(1) Because of its extremely fine particles, its texture is very delicate, which is what the ancients called "fine chestnut", which is beyond the reach of other jade.

(2) warm and humid. It is oily luster, giving people a moist and soft feeling. The ancients called it "moist and shiny", and sheep fat jade is famous for moistening jade like sheep fat.

(3) Moderate transparency. That is, the "good head" is slightly transparent. The carved jade pieces look watery and lively.

(4) Very few impurities. Some of them are perfect and consistent inside and outside, which is what the ancients said, "flaws don't cover up Yu, yoga doesn't cover up flaws", or "cheeks can learn from others."

difficulty

Hardness is one of the important signs to identify Hetian jade, which refers to the ability of minerals to resist the invasion of external mechanical forces (such as carving, pressing and grinding). ) Mohs hardness commonly used in gemology refers to engraving hardness. In the jewelry industry, hardness is generally regarded as an important symbol to distinguish gems from jade. The hardness of gemstones is generally above 7 Mohs, and the hardness of jade is generally 4-7 Mohs. Hardness below 4 Mohs is usually called colored stone or carved stone. High hardness and good polishing performance can make jade shine and facilitate long-term storage.

The Mohs hardness of Hetian jade is determined to be 6.5-6.9, and the hardness is relatively large, with slight differences among different varieties. Generally speaking, the hardness of sapphire is slightly greater than that of white jade.

stick to

Toughness is usually the inherent bonding ability of jade, that is, the ability to resist external pressure or crushing force. Toughness is characterized by hard fracture and wear resistance. Nephrite has great toughness, which other jadeites do not have, and can be used as a fine workmanship. ?

The great toughness of Hetian jade is inseparable from its unique felt-like structure. Toughness is not easy to break, but also wear-resistant, which is of great benefit to the artistic modeling and fine carving of jade, and is an important factor for Hetian jade to be listed as a group of jade.

References:

Hotan jade-Baidu encyclopedia