The quality of jadeite is generally judged from five aspects: texture, hardness, transparency, specific gravity and color. The texture of jade refers to the delicate and moist degree of jade. One of the differences between jade and stone is that jade is delicate, moist and hard, translucent and glossy as fat; Stone, on the other hand, is rough and dry, lacking luster and opaque. Hardness refers to the ability of jade to resist external forces (such as pressing, engraving and grinding). The higher the hardness, the more difficult it is to process and the better the quality of jade. Although the hardness index of jade can be known by detecting its internal crystal structure with instruments, the method of scraping hardness is generally used in operation. The hardness of common jade in China is between 4 and 6 degrees, which is higher than copper and lower than glass. In other words, jade can be carved on copper and glass.

To identify the quality of jade, the British and American Jewelry Association has four standards: "color, transparency, uniformity and shape". In China, there are six standards, namely "color, transparency, uniformity, shape, percussion and luster".

1. No matter what color of jade it is, it must be bright. "White as fat", "yellow as steamed millet", "green as jade" and "black as ink" are excellent summaries of jade color by the ancients. Mottled, dark, not good. Among all colors, green is the best jade. Red and purple are one fifth as valuable as green. Jade with four colors is called "Fulu Xi Shou", and if it contains only three colors of red, green and white, it is called "Fulushou".

2. As transparent as glass, it is called jade, which is the top grade. Translucent and opaque jade is called intermediate jade or ordinary jade. Before the Qing Dynasty, red, green and white were called jadeite. Now jadeite jade refers to transparent jade, most of which are transparent green.

3. It even means uniform color. The color of jade is uniform. If it contains green but the color is uneven, its value is very low.

The bigger the shape, the more valuable it is and the thicker it is.

There are often cracks and cuts when you knock on jade. These cracks are generally not easy to observe. When knocking, you can tell whether there is a crack by the clarity of the sound.

6. There are black spots and flaws on jade that are not easy to be found by naked eyes. You can see it at a glance as long as you take pictures with a magnifying glass 10 times in light (avoiding strong light).

In addition, when buying jade (such as jade edge and jewelry), we should also pay attention to the craft. Jade products pay attention to exquisite and unique shapes, vivid images, distinct levels, patchwork and elegant decoration. Use color, be clever because of color. Shallow carving, though flat as a mirror, should be far from Jing Yi. Hollow out, exquisite and realistic.

When buying jade, don't do it in bright light. Because light irradiation is easy to make jade lose its primary color and even cover up some defects. The so-called "beautiful jade under the lamp" is the truth.

Tip: Jade is cold. Put a head on it, burn it with a lighter, and keep burning at the jade head.

Professional evaluation

Ancient jade appraisal has several points:

First, process trace identification

Second, the oxidation identification

Third, the identification of condensed water

Fourth, the evaluation of artistic level.

Five, Qin color identification

Sixth, odor recognition.

Which is divided into (1), modeling and discrimination. (2), jade, jade material discrimination (3), decoration discrimination (4), style discrimination.

The identification of Qin color focuses on learning and understanding the color change between ancient jade and objects that have been in contact with various storage environments for a long time, but it is actually a physical phenomenon, and the natural quality change it produces is color change. We usually call it "Qin color". For example, ancient jade stored in red paint may be red, black paint may produce black, and buried in loess may produce yellowish brown mud. Observing under strong white light, Qin color usually occurs in the place where jade contact is weak or naturally cleavage wrinkles. Then along the cleavage or fissure, the penetration expands, which can seriously soak the whole organ, which is called "total immersion". After playing, the color is bright, and the color of the piano mostly changes from gray to red. The important point is: under normal circumstances, genuine products are relatively simple; The darker the color, the more chaotic the piano color and the bright piano color are questionable. Even if the real jade has cleavage and cracks, it is not a contact part and does not necessarily have bright colors. Imitate the color of the piano by chemical or physical methods, usually the whole piano. There is also local soft mud, which is characterized by its Qin color. It is not necessary to burn pseudo-ooze in the soft rib or crack of jade. This can be observed under intense white light. However, it is useful to forge the Qin color by laser along the cleavage or fold of jade with high technology. Another point is that the storage environment of jade is dry or jade is dense. Look at the color: natural jadeite has natural color, uneven distribution, prolonged green trend and generally no fluorescence.

Look at the polished surface: the polished surface of natural jadeite is fine and smooth, with grease showing a strong glass luster. If you look closely at the polished surface, you can usually see the mottled crystal interwoven structure. In general, the variegated crystal particles of the same jadeite are uniform in size; At the same time, slightly transparent to opaque white fibrous crystals can be seen, commonly known as "stone flowers".

Listen to the sound: tap the natural jade gently, making a crisp and pleasant sound. If it is artificially processed, it will make a dull sound.

In addition, because of the high density of jadeite, it feels like a thug by hand; Jade has a strong water-holding ability. When it drops on it, the water drops protrude higher.

At the same time, experts remind consumers that when buying high-priced jewelry and jade, they should choose regular and well-known jewelry stores or large and reputable shopping malls. Also remember to ask the merchant for the jewelry and jade appraisal certificate with "CMA" and "CAL" marks. Usually, every precious jewelry and jade has a certificate to ensure that the purchased jewelry and jade are consistent with the certificate, and the certificate is accompanied by photos.

First-class jade, moist, thorough and greasy, is moist in your hand. The main method to identify the authenticity is to use a magnifying glass or microscope to see that there is a fiber interwoven structure inside the jade, and the particles are fine; Artificial glass has no structure and bubbles can be seen. You can also carve it in an inconspicuous place with a knife. What can be carved must be fake jade, but what cannot be carved is real jade. As the saying goes, "Gold is valuable, but jade is priceless". Because the top grade Hetian jade is getting scarce, it can reach tens of thousands to hundreds of thousands of yuan per kilogram, while the average Qinghai white jade and Russian white jade are only a few thousand yuan per kilogram, so some people mix it with Hetian jade. The minerals of these jadeites are basically the same as Hetian jade, but the surface color is dark and not soft, which will be even dimmer after a long time.