These are the four types of jade that you absolutely cannot have! Remember!

I believe it is common knowledge that you should remember to get an appraisal certificate when purchasing jadeite. Generally speaking, according to national standards, NGTC quality inspectors will give five types of inspection conclusions, including natural jade, jade (processed), spliced ​​jade, synthetic jade, and imitation jade . Today, the editor will explain them to you in detail.

Natural Jade

Natural jade, also commonly known as A-grade jade , refers to jade that has not undergone any artificial processing other than cutting and polishing . You can rest assured when you see this inspection conclusion. No matter what its value is, at least it is real.

Jade (processed)

As the name suggests, it is jade that has been processed . The processing methods include dyeing, bleaching, filling, coating, etc. For jade that has been artificially processed, the processing method will be indicated in the "Remarks" column. Next, let’s focus on coated jadeite.

▲ Film-coated jadeite

Coating is the process of applying a thin organic layer to the surface of jade to improve color and transparency, hide internal or external features, and present an attractive luster. With the development of coating technology in recent years, it has become possible to better remove bubbles between the film and the gemstone, and adhere more firmly to the gemstone material.

▲Laminated (left) and unlaminated (right)

Although the appearance is improved, under magnification, the surface of the coated jade usually shows fine scratches or even partial peeling . These irregular scratches are different from the polishing lines of uncoated jade.

▲ Visible scratches on the surface of coated jadeite

Under long-wave ultraviolet light, the coating exhibits a weak light blue fluorescence , while the internal jade exhibits a yellowish green fluorescence . At the same time, the hardness of the coated jade is much lower than that of natural jade (about 7).

▲ The coating partly falls off

In addition, the coated jade feels dry and rough, and due to the poor thermal conductivity of the coating, it feels warm, which is different from the smooth and cold surface of natural jade , so it can be distinguished by touch.

Jadeite

Composite jade is made of two or more pieces of materials that are artificially pieced together . R. Werbster (1962) recorded in detail a three-layer composite jade stone in his book "Gems": the top layer is arc-shaped white jade, the bottom is hollowed out to form a concave arc, the concave arc is coated with green glue, and a matching arc-shaped white jade is glued on as the inner core, and then a piece of jade is used to seal the bottom.

R. Werbster believes that this three-layer stone is more difficult to identify than dyed green jadeite , especially when the bonding line on the waist is covered by the inlay method. This kind of composite jade has visible light absorption spectrum characteristics similar to those of dyed jade, which can be used as a basis for identification.

Around 2002, a new type of composite jade called thin-skinned jade appeared on the markets in Hong Kong and Taiwan. It was made from green but less transparent jade, and was made into a hollow ring face that was almost the thickness of an eggshell. It was filled with resin glue and inlaid with a sealed bottom. After light penetrated the thin-shell jade, it was reflected again to form a light band on the surface.

However, the durability of this new type of composite jade is poor. After a period of time, due to the large difference in thermal coefficients between jade and resin, the thin layers of jade are prone to cracks .

Synthetic Jade

As early as 2015, the General Electric (GE) laboratory in the United States announced that it had successfully synthesized jadeite . This synthetic jade is completely artificially made. Its appearance and composition are no different from natural jade. It can pass instrument testing and issue a certificate , which caused a sensation at the time.

▲5.20 carats of gem-quality synthetic jadeite produced by Qiyi Company

Artificial synthetic jade is made in a similar way to diamond under a high temperature of 1400 degrees and ultra-high pressure (ultra-high pressure is generally considered to refer to pressure above 10 kilobars).

After testing, the finished product is exactly the same as natural jade in terms of composition, structure, hardness, refractive index, specific gravity, absorption spectrum, etc. Unless high-end detectors are used, it cannot be identified by the naked eye or general methods.

The reason why synthetic jade has not been put on the market since its success is that, on the one hand, the structure of jade is too complex and the conditions are harsh, which is much more difficult than making a single crystal gem, resulting in the cost of synthesis being too high.

On the other hand, most synthetic jades have a rough texture and poor transparency. Many synthetic products have black or dark centers, and the degree of crystallization is uneven, which seriously affects the quality of synthesis and does not meet the standards of gem-grade jade.

Look at these laboratory-synthesized jadeites. The green is indeed green, but the quality is rough, the water content is poor, and there are many impurities, a bit similar to Tielongsheng. Even if such jade is put on the market, no one will buy it.

Imitation jade

Imitation, that is, counterfeit, refers to some artificial gemstone (such as glass, etc.) or jade imitation of similar jade . For example, dyed quartzite is made by adding colorant to melted pure quartz or quartz crystals. It is also called Malaysian jade, Malay jade, Luzon jade, etc. It is one of the most common jade imitations.

This dyed quartzite usually appears translucent green. Because it is dyed, the green dye can be seen distributed in the quartzite like filaments through the light, which is too bright and very unnatural.

At the same time, in terms of physical properties, the specific gravity of dyed quartzite is smaller than that of jadeite, and its refractive index is also lower than that of jadeite. It is very different from the real jadeite, and experts can distinguish it with the naked eye.

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