One article to understand jade A, B, C, glass, ice, and sticky, as well as how to identify real and fake jade

The Chinese nation is a jade-loving nation. No other nation in the world has linked jade with national culture and character as closely as the Chinese nation. “Jade has no virtue,” “A gentleman compares his virtue to jade,” and “In ancient times, the characters for jade and king were the same.” In Chinese culture, jade is not only a symbol of a gentleman, but also a symbol of a king. Because of the Chinese people's love for jade, jade has become the third largest collection of handicrafts after calligraphy and painting and porcelain.

Jadeite, also known as jadeite jade, jadeite and Burmese jade, is a type of jade. The correct definition of jadeite is a fibrous aggregate composed of pyroxene minerals, mainly jadeite minerals. But jadeite is not the same as jadeite. Jade is a stone polycrystalline aggregate that reaches the jade grade under geological action. It is mainly composed of jadeite or jadeite and sodium (sodium chrome pyroxene) and sodium calcium pyroxene (diopside). It may contain amphibole, feldspar, chromite, limonite, etc.

In ancient times, jadeite was a bird that lived in the south. It had very beautiful feathers, usually in colors such as blue, green, red, and brown. Generally, the male of this bird is red, called "fei", and the female is green, called "cui". The Tengyue Local Chronicles written by Cun Kaitai records: "Teng is the gathering place of jade, with more than a thousand jade craftsmen who make utensils and sell them to various provinces in Yunnan. The best quality jade is mostly sent to eastern Guangdong, Shanghai, Fujian, Zhejiang, and Kyoto. By the end of the Qing Dynasty and the beginning of the Republic of China, there were more than a hundred jade workshops and more than three thousand jade carving craftsmen in the city of Tengchong alone. The utensils they carved were sold to various provinces in Yunnan." "Tengyue Local Chronicles" written by Cun Kaitai records: "The jade produced in Menggong and Myitkyina in Myanmar is only 150 kilometers away from the Yunnan border of our country. During the Wanli period of the Ming Dynasty, this place was under the jurisdiction of Yongchang Prefecture (now Baoshan City, Yunnan Province). Due to historical reasons, jadeite, known as the "Oriental treasure", has been imported into my country through border towns such as Tengchong and Ruili in Yunnan for four or five hundred years.

When we buy jadeite, we are always confused by some jade merchants who are not "open-minded". For example, they often talk about A-grade, B-grade, C-grade and B+C-grade, as well as ice-type, glass-type, glutinous-type and so on. This article will explain these seemingly confusing things one by one, and will give a detailed explanation of how to identify the authenticity of jadeite. After reading it, these problems can be easily solved.

A-grade(Allowing):

A-grade jade refers to naturally produced jade, which is processed, carved, ground and polished using physical methods without using any chemical or radiation methods to improve its internal structure. It has a strong glassy luster, a clear and pleasant sound, and the cotton wool inside is similar to the shape of a fly's wings. The quality of A-grade jadeite can be judged from its transparency, clarity, color, and appearance.

The new type of A-grade jade (belonging to B-grade jade) refers to A-grade jade with color added to the part with colored roots. It is particularly important to note that this type of colored jade has no fluorescent reaction and does not change its specific gravity. A lax appraisal agency will issue a "Jade A Certificate". This type of jade is commonly sold in the jewelry market and even in many famous stores. If you are purchasing collection-level jade, be careful.

B-grade jadeite (Bleached and Polymer impregnated jadeite) is jadeite that has been acid-washed, bleached and injected with glue to remove impurities.

C goods (Coating jadeite) are dyed. To dye jade. Regardless of whether it is acid-bleached or not, or filled with glue or not, any jadeite that is artificially colored is called C-grade jadeite.

B+C goods refer to jade that has been bleached, filled and dyed. It is acid-washed, bleached, filled with glue and artificially dyed. It looks beautiful in both color and water content. It is a good piece of inexpensive jewelry, but it has no collection value. B+C grade jadeite, whose national standard name is "jadeite (filled and dyed)", refers to natural jadeite that has been bleached, filled and dyed, which changes its appearance.

Choosing Jade

There is a saying in the industry that goes "one kind, two colors, and three craftsmanship. The type of jade is important for bracelets, and the color is important for pendants." It can be seen that the type, color, and craftsmanship are the three most basic factors in choosing jade, followed by size and weight, uniformity, clarity, cracks, and aesthetics.

1. Look at the water

“Good quality jade can cover up three flaws” vividly illustrates the importance of jade quality.

Water head, or transparency, refers to the ability of jadeite to transmit visible light. There is a saying in the industry: "Look at the type of bracelet and the color of pendant". This shows the importance of water head in jade bracelets. A bracelet with good water head can make women look younger and more energetic.

The grades from high to low are: old pit glass type, water type, ice type, ice glutinous type, glutinous type, and other types. The quality of other types mainly depends on the color.

2. Color identification

Jade comes in many colors, but the best jade is generally dominated by bright green. However, green means very different things to women of different ages, body shapes, and temperaments. When purchasing, you should choose according to your own preferences. Young women are better off choosing bracelets with brighter colors and good water head to appear youthful, energetic and full of vitality; older women should choose bracelets with slightly darker colors to appear noble, dignified and steady.

The color grades from high to low are: green (imperial green, positive green, apple green), red, yellow, and purple.

3. Look at the craftsmanship: There is a saying that "material and craftsmanship are half and half", which means that for a good work of art, the value of materials and craftsmanship each account for half; the quality of craftsmanship and its symbolic meaning both affect the price.

4. Others: Size and thickness, that is, jade of the same quality will of course have a higher price for larger and thicker ones; uniformity, that is, the water and color are evenly distributed, and the better; clarity, that is, there are no flaws and other colors, the cleaner the better; willow cracks, that is, the free of cracks is better; aesthetics, that is, the overall feeling of the jade object in many aspects, which also varies from person to person. It is very useful for jade lovers to master the correct methods of jade identification. Here is an introduction to the identification method of jadeite, I hope it will be helpful to everyone

1. Gloss. After being soaked in strong acid and alkali, the structure of jade becomes loose, and before filling, corrosion pits appear on the surface, causing diffuse reflection and weakening the luster. After adding organic fillers such as resin or plastic, jade often has resin luster, waxy luster, or a mixture of glass luster with resin luster and waxy luster.

2. Color. Since the structure of jade is destroyed, the original optical properties are also changed, so the color distribution of "B-grade expanded jade" has no sense of hierarchy. Although the green color of jade treated by this method is still the original color, after being soaked in acidic solution, the base becomes white, the green distribution is more floating, and the original color orientation is also destroyed, which looks very unnatural.

3. Structure. When jade is soaked and corroded by strong acids and alkalis, some substances are brought in and out, causing dissolution along the mineral crystals on the surface and inside, resulting in internal interconnected cracks. Under transmitted light, the crisscrossing cracks inside can be seen. Under reflected light conditions, the surface dissolution pits or spider-web-like patterns are clearly visible.

4. Surface characteristics. Jadeite treated by this method has obvious grooves at the original cracks due to the large difference in hardness between the filler and the jadeite itself. The filling is obviously lower than the two sides, and many cracks form criss-crossing ditches. Cementation or residual bubbles can be seen in the larger "ditches". The surface of jadeite treated with bleaching and filling with better processing technology is very smooth, without the above phenomenon, and requires more careful observation and measurement.

5. Density and refractive index. Most jadeite that has been bleached and filled has a slightly lower density and refractive index. The density is 3.00~3.43g/cm, and the refractive index is about 1.65 (point measurement). However, due to the complex mineral composition of jade, the density and refractive index values ​​of some natural jade may be low. Therefore, the density and refractive index can only be used as reference data and usually cannot be used as a basis for determining whether jade has been filled.

6. Fluorescence. There is no or weak to strong ultraviolet fluorescence, and the fluorescence distribution is uniform or mottled. Most of the early "B-grade" jadeite has fluorescence. Short wave: weak, yellow-green or blue-green (blue-white); long wave: medium to strong, yellow-green or blue-white. However, jadeite treated by this method usually has weak fluorescence or no fluorescence.

7 Zoom in and check. Magnified Inspection Magnified inspection is an effective method for identifying this type of treated jadeite. It is divided into surface observation and internal observation.

8. Thermal reaction. When "B-grade" jade is heated to 200-300℃, the gum will carbonize.

9. Tap response. The structure of jadeite is destroyed after bleaching and filling, and the space between the mineral particles is filled with colloid. Therefore, it will make a dull sound when tapped gently, which is significantly different from the crisp sound of natural jade (this method is mainly suitable for identifying jade bracelets).

When identifying A and B grade jadeite with the naked eye, the characteristics of both A and B grade jadeite often appear together. At this time, you should first adopt a skeptical attitude, and then conduct repeated and detailed observations patiently and carefully.

To identify jadeite A, B, C and B+C, you can look at the following aspects:

1. Soak in boiling water for a few minutes. If the color in the water begins to dissolve and the colored parts of the jade fade dramatically, it definitely means that it has been dyed and is a C grade jade.
If there is a colloid floating in the water after soaking it in boiling water, or if the surface of the jade becomes sticky and has an abnormal burnt smell after being burned with a butane gas lighter, it is definitely a B-grade jade that has been filled. If both phenomena occur, it is a B+C grade jade.
2. Use a butane gas lighter to burn unprocessed natural jade. (Do not use natural gas, artificial gas, candles, matches, gasoline lighters, etc. that easily produce smoke and blacken objects.) Generally, the burning time should not exceed 10 seconds. (If the time is too long, it will easily damage the crystal structure of the jade, and the internal crystals will oxidize and the color will turn black.) The natural crystal minerals that form jade are resistant to high temperatures. Even if there are black marks on it after burning, you can wipe the black marks with a dry cloth and it will immediately restore its original luster without any change. However, jade filled with epoxy resin polymers will emit oil smoke during the grilling process, and black gelatinous substances such as burnt epoxy resin polymers will ooze out on the surface. This identification method can basically identify B-grade jade.
3. Use a sharp knife to scrape the surface of the jade. If it is processed jade, there must be something on the surface of the jade that can be scraped off by the sharp knife. Because artificial processing or dyeing are all processed with epoxy resin glue. Epoxy resin glue treatment mainly treats the surface of jadeite and cannot completely penetrate into the interior of jadeite. The surface hardness of natural jade is harder than that of ordinary steel knives. If it has been processed, the surface of jade will be filled with a large amount of resin glue, and it will not be as hard as natural jade. A sharp steel knife can scrape off the processed part of the surface. In other words, if you can scrape off some particles from the surface of jade, it proves that the jade is B-grade jade.
4. How to identify jadeite dyed by the dyeing method: Put the dyed jadeite into nitric acid or sulfuric acid, and the green color will fade after a few hours. If you place the brown jadeite on an iron container at 70-80℃, the green color will fade after a few hours. These two characteristics can be used to distinguish between salted jadeite and natural jadeite.

fcgc66

fcpf18