Since the 1980s, the biggest challenge faced by gemologists is not similar to the problem of stone identification, but the technology of manual treatment of gems has emerged one after another, and almost many important gems have manual treatment problems. This is because with the development of science and technology and the improvement of people's living standards, people's demand for jewelry has increased sharply, so many new technologies have been applied to the manual treatment of gems. For example: heat treatment of gemstones; Radiation-treated gems; Laser treatment of gemstones; Glue and glass are used to treat gems. Nowadays, diamonds, rubies, emeralds and other precious stones are all facing the problem of manual treatment. It is the most difficult to identify the artificially processed gem because its material is natural. It's just that a defective or low-grade gem has been artificially added with artificial elements to improve its appearance (such as changing color and improving cleanliness). ) and raise its price. Not completely fake, the material is natural, the quality of the gem is fake, and the durability may be reduced. Its appearance can deceive people and its image is realistic, which has aroused great concern in the industry. It is difficult for ordinary people to find this kind of artificial gem, and it is also difficult for ordinary gem appraisers to identify its defects with ordinary instruments, so gem experts are forced to turn to higher and newer technology for help. It can be said that "the road is one foot high and the magic is one foot high."

The problem of jadeite industry is that jadeite was soaked in acid and resin in the early 1980s. At that time, the market in Taiwan Province Province of China began to open, and the mainland market was also opening. A whirlwind of "B" grade jadeite has been blown up in the Hong Kong market, which has filled the developing jadeite market with smoke. Profitable profiteers seized this unknown opportunity and sold this artificially treated low-priced jade as "A" jade, making a big profit and making a windfall.

But at the same time, many people were deceived and suffered heavy losses, which made consumers lose confidence in jade. Japanese trade associations once banned the import of jadeite from Hong Kong, which caused great damage to the jadeite industry.

As a scholar of jadeite and a disseminator of jadeite culture, Bian Xiao can't bear to see unscrupulous businessmen. In order to make huge profits, he will not hesitate to make natural jadeite into resin and sell it as natural jadeite, deceiving consumers and distorting the facts. This treated jadeite will lose its durability and crack will appear after a few years. It has made huge profits for some people, but it has caused a great blow to the entire jade market and made consumers lose confidence.

Second, optimize heat treatment.

1.

Burning red jadeite has a long history, and it is mainly used in jadeite to obtain pure red jadeite. Traditionally, people in China like red very much. It is a symbol of good luck. Pure red is extremely rare in nature, and it is often a layer of "mushy" red under the epidermis of jadeite raw materials, mostly with brown or tan. Pure red jadeite can be obtained after heating. This heating treatment does not add any dye, does not damage the structure and durability of jadeite, and does not fade, which is traditionally acceptable.

2. Method

(1) Seed selection: Not all jadeite can be heated to turn red, but it must be yellowish brown or brown jadeite;

(2) Cleaning: All oil stains should be thoroughly cleaned.

(3) Heating in the furnace: You can use an ordinary furnace, and it is best to spread a layer of sand on the furnace surface to ensure that the temperature rises and falls evenly during heating, and the jadeite to be treated is placed on the sand layer. Generally speaking, heating is carried out under oxidizing conditions, so the temperature rises slowly. Later, carefully observe the color change of jadeite. When heated to a certain high temperature, jadeite will slowly change color, and the original color will turn red.

(4) Soak in bleach for a period of time: In order to get sufficient oxidation, sometimes the heated sample will be cooled and soaked in bleach water, and the red color will be more beautiful and bright. Natural red is called raw red by experts and cooked red by people after heating.

3. Principles

Yellow-brown or brown jadeite is caused by limonite contained between particles. When heated under oxidizing conditions (about 200℃), it can be transformed into red hematite, that is, red jadeite can be obtained.

4. Inspection method

After heating, the color of jadeite can be transformed into pure red, but the transparency is poor, which is slightly different from natural red, but it is generally difficult to distinguish. The industry generally doesn't care whether Redjade has been heated. The key is not to add any coloring agent and not to destroy its function.

Third, dyeing treatment.

1.

One of the main factors that determine the value of jadeite is to see how many boxes of its color are bright, and most jadeites are colorless in nature. Therefore, since ancient times, in order to cater to some consumers, some jadeites have been dyed in various colors, such as green to raise the starting price, and some have been dyed purple and red.

2. Method

(1) Choose the right jade species, not all jade species can be dyed well.

(2) washing with weak acid.

(3) Boil the soap in water mixed with soap powder, then take it out, wash it and remove the oil.

(4) Put the cleaned jade into a heating furnace and heat it slightly. According to the principle of thermal expansion and cold contraction, the pores between particles expand, and sometimes vacuum is needed.

(5) Soak in the solution of chemical dyes (such as chromium oxide salt), including oil and powder, mostly organic dyes, and the soaking time varies from two weeks to one week.

(6) After being taken out, it is put into white mineral oil or bleached water for further oxidation.

(7) Wash with clear water and soak the wax.

3. Principles

Emerald, like agate and other gems, is a polycrystalline gem, which consists of many tiny fine crystals. Therefore, people use the chemical treatment method to soak the gemstone in the dye, and let the colored solvent slowly soak in the pores and microcracks of the gemstone, so that the gemstone becomes discolored. This is dyeing, which is also called "coloring".

I told you so many steps and processes of jadeite dyeing. Now I'll tell you how to distinguish the method of jadeite dyeing.

Inspection methods and steps of dyed jadeite jade

The first step is to observe the sample completely with naked eyes to get the subjective feeling: (1) Tone: natural color? Is green blue? Is purple red? (2) looking for cracks? Is there any dye in the crack? (3) Is the color distribution reasonable? Does the variety match the color?

Step 2, do some observation under the lamp with a magnifying glass-find evidence: (1) find the relationship between crystal and color, and whether the color at the junction between crystal and crystal is dark. 1) Often, the inner color of the crystal is light, and the possibility of dyeing is greater. 2) The boundaries between crystals are light in color, and there is no dye.

Purple Emerald: Observe the relationship between purple and crystal under reflected light. Does white surround purple or purple surround white? According to my experience, if white surrounds purple-natural purple. If purple surrounds the white dye.

Step 3, instrument observation-Charpy filter observation.

Observe the green jade: (1) The color of the sample is red, indicating that there may be dyes. (2) The color of the sample remains unchanged, indicating that there may be no dye.

Observe purple jadeite: the color filter has no effect on the identification of purple jadeite. But it has a certain effect under the long wave of ultraviolet lamp. Because purple jadeite is dyed with manganese-containing dyes, it will show orange to pink fluorescence under the long wave of ultraviolet lamp, which can be used as an indicator. Natural purple jade has no fluorescence, but explain that natural purple jade sometimes has fluorescence, which may be caused by some special solutions infiltrated during processing, so be especially careful.

4. Bleaching and resin treatment -B jadeite.

To identify Emerald B, we must know its origin and development, so as to master its regularity.

1.

Technically speaking, it is to achieve the following effects or one of them, thus increasing the price of jadeite.

(1) yellow gas removal: the yellow film is removed. (2) Decontamination bottom: Remove the gray or black bottom. (3) Removing water stains: removing white sediment. (4) Improving germplasm: increasing transparency.

2. Method

(1) Selection: Which germplasm are suitable for B or B? Not all germplasm can be used as jadeite B, such as:

1) Consider the economic effect: Is it necessary? 2) The process effect should be considered: whether it can be done or not should be considered.

In the early days, jadeite with dirty bottom will be regarded as grade B jadeite. For example:

A. "Green seeds with eight or three flowers": characterized by white background, some purple flowers and irregular dark blue floating flowers. Most of them are rough, dry and moisture-free, and no one likes them without artificial treatment. But once soaked in resin, their germplasm becomes transparent and crystal clear, and the process effect is good. Therefore, a large number of "March 8" B-shaped jade bracelets have appeared on the market. Because of its large volume, this raw material is widely used to make bracelets. But as long as you know about 38 kinds of raw materials that are not made into B goods, it is easy to know whether they have been impregnated into the resin of B goods jadeite.

B. Wusha species: There are often many stains at the bottom. If it is dirty, it can be washed away by acid soaking, and the color becomes much brighter, but not all kinds of jadeites in Wusha should be made.

C. Green species on a white background: Because the cyan part on a white background is generally bright, its background color is white. If there is yellow covering the white part, its aesthetic degree will be reduced.

D. Anthurium species: it has a white background or a light green background, and then it is irregularly distributed in green. If its background color is "dirty" or "yellow", it is also used to make B jade.

E. Cat bean seed: It is thick after the festival, and the background color is often dirty. If it is not bleached, its value is low. After bleaching, its background color can be clearer and its value can be improved.

F titanosaur species: titanosaur species jadeite, a new variety, is now used to make B-grade jadeite. It's not because it's dirty that it needs to be washed. Mainly low-grade Tielong jadeite, with coarse particles, loose structure, opacity and no moisture. The purpose of resin is to improve its germplasm. After adding resin, its structure is denser, its transparency is higher and its color is brighter.

(2) Acid leaching: according to the selected samples, wash them with water and put them into strong acid, and soak them with concentrated hydrochloric acid or sulfurous acid according to different germplasm. The soaking time is different, usually four weeks, and the soaking conditions are different according to the needs. For those with less yellow pollution, those with short soaking time, those with less damage, and those with long soaking time, jadeite is soaked alternately with alkali tension. This stage is the process of jadeite being corroded by strong acid and alkali. The function of alkali can make the structure of jadeite become very loose and honeycomb-shaped. Its original structure has been destroyed, and as a result, it can be washed very clean and turned into a powder jade stage.

(3) Washing: Wash the acid solution with clear water.

(4) vacuumizing: the purpose is to make the pores between particles have no air and allow the resin to penetrate evenly.

(5) Resin cementation: Due to the loose structure, a resin with strong adhesion is needed for cementation, generally epoxy resin, and the epoxy resin used now has been greatly improved.

(6) Heating: put it on tin foil and heat it in a microwave oven, so that even if the resin condenses, excess resin will flow out.

(7) Cleaning resin: scrape off the resin visible to the naked eye with a knife.

3. How to identify B jadeite?

According to my years of experience, it is very important to identify species. Knowing the types of jadeite means knowing all kinds of natural jadeite. When you pick up the jade you have observed, you must first see whether it can be restored to its original species. As for me studying in the jade processing factory, I hope I can learn to identify B-grade jadeite with the naked eye.

(1) completely observed with naked eyes.

1) Is the color normal? After bleaching, jadeite generally looks fresh and unnatural, with a yellowish feeling. If there are both green and white parts in the sample, people feel that the boundary between green and white is particularly clear or very clear, and the diffusion of green parts is unnatural. Below: It's too clean.

2) Gloss-strong or weak reflection: With the same texture, the reflection of jadeite from A goods is stronger, while that of jadeite from B goods is weaker; You can detect it by shaking it slowly in the light. Waxy luster or resin luster is different from jade without resin-it has glass luster.

3) Transparency-Is it normal? B Jade is not very transparent (glass bottom) because of resin. At this time, I will give you a concept of whether the color germplasm can be matched, which gives me an impression that it is A or B.

(2) Magnifying glass observation-choose some points to observe, mainly to find evidence. Is your subjective feeling right?

1) observation of surface pits and surface cracks under reflected light: due to the treatment of strong acid, some jadeite aggregates with poor acid resistance, such as feldspar, may be corroded first. Therefore, a pit can be observed under the reflected light of the magnifying glass, which is called "trachoma" in jargon. However, it should be pointed out that there are also sand holes in the bean-thick A-type jadeite, and the proportion is only small. After a period of acid treatment, the jadeite put into the resin will have irregular cracks on its surface, which are called cracks and are generally not deep. This is an important feature of B jadeite, which is related to the aging of resin. But this can't be conclusive evidence, so we should use it carefully.

2) Under the transmitted light, observe the internal iron staining phenomenon with a magnifying glass: dark jadeite often has iron staining (called cat water in the industry), and there is yellow iron staining in the cracks, which proves that the finished product has not been bleached, otherwise it is impossible to have iron staining. But it should be noted that sometimes yellow is dyed to make it look like yellow. Generally speaking, bleached jadeite is cleaner.

3) Whether the crystal structure is destroyed:

A. The structure of natural jadeite can be divided into two categories: granular metamorphic structure and fiber metamorphic structure.

B. The jadeite with granular structure mainly observes whether the jadeite particles are obvious or fuzzy. The structural boundary of natural jadeite is obvious, but the boundary of jadeite cemented with resin after acid etching is not obvious, which is the characteristic of grade B jadeite.

For jadeite products with fiber structure, it is generally easy to observe that the particles are slender and the crystals are damaged, but it can be seen that the crystal arrangement is damaged and the fibrous crystals are not oriented, which is an important sign of artificial bleaching treatment. In fact, at this stage, people with certain experience can already identify jade B.

(3) Instrument test method

1) specific gravity method: Because the impurities in the bleached jadeite are taken away and the structure is loose, some resin is added, so the specific gravity is lighter than the original. Generally, the specific gravity of 3.33 can be used as the standard. Most of the bleached jadeite jadeite jadeite is lighter than 3.33, but the dark green jadeite will be higher than 3.33. This method can get more evidence that jadeite is a or b goods.

2) Ultraviolet lamp: Observe the fluorescence of jadeite, because resin can stimulate ultraviolet fluorescence. Observing the color, distribution and intensity characteristics of fluorescence is helpful to identify jadeite B, but it must be noted that jadeite A may have fluorescence and jadeite B may not. The fluorescence caused by resin is milky white, the fluorescence caused by coconut oil is orange yellow, and the fluorescence caused by mineral impurities is distributed locally. Some chemically treated dark green jadeites contain certain iron ions, so the fluorescence of jadeite is inhibited, while dark green B jadeite has no fluorescence.

3) Infrared spectrometer: Infrared spectrometer is a relatively new instrument, but it is expensive. When different substances are irradiated by infrared rays, the number of absorbed light quantum is different (that is, the wavelength is different). There are two different methods to identify grade B jadeite by infrared spectrometer, namely, transmitted light method and reflected light method.

Using infrared spectrometer to identify jadeite can be said to be a relatively objective method and a relatively fast method. But it can only prove the existence of resin.

Natural jadeite is an aggregate of sodium aluminosilicate minerals and contains no organic matter. For example, the absorption line of resin in the infrared spectrum curve of jadeite can prove that it contains resin. Although there are many kinds of resins, four known resins are usually used to make B jadeite.

The identification of jadeite B by infrared spectroscopy is judged by observing whether the sample belongs to jadeite by other methods, such as refractive index, specific gravity and structure. The infrared absorption characteristics of the resin are that the absorption peaks of 2870, 2928, 2964, 3035 and 3508 cm- 1 are displayed in the range of 2200~3500. Therefore, as long as there are several strong absorption peaks in the range of 2800~3200, it can be judged that no resin is A goods. If there is an absorption peak of resin, it means that the jadeite sample contains organic resin, which means that jadeite belongs to B goods. Of course, be careful and do more tests.

Five, pickling and dyeing into resin treatment (B+C)

The green color of B jadeite mentioned earlier is to keep the original color without adding any coloring agent. The B+C jadeite referred to here is the jadeite that has been dipped in acid and dyed with resin, and its color is artificially colored with resin, which can be said to be a double fake.

1. Manufacturing process and steps

Step 1: Soak colorless or light-colored jadeite in strong acid and alkali, in order to loosen it by natural washing, so that it can be colored and glued.

Step 2: Method a): completely immerse the jade powder in the dye solution, so that the dye solution penetrates and the color is uniform. Method b): Use a brush to dip the dye solution on the powder jade, slowly soak it for dyeing, and optionally dye it locally.

There are two kinds of green dyes used: (1) chromium salt, which turns red under the color filter. (2) Organic dyes-will not turn red under the color filter. Purple: organic dye. Red: iron oxide.

Step 3: inject resin.

2. Identification of B+C jadeite (dyed into resin)

The method is basically the same as the identification method of goods B, and several identification methods are added.

(1) Full observation with naked eyes: get a subjective first impression. Dyed green, the color is often too bright and unnatural. Much brighter than undyed B-goods, and brighter than jadeite dyed by hand. Because the bottom after pickling is clean and artificially colored, it is unnatural and easy to feel. People who dye purple can see that purple is evenly distributed. In a word, the relationship between color and germplasm does not conform to the relationship between jadeite in nature. It is difficult to restore its original species.

(2) Color filter observation: B+C goods are dyed green, and most of them cannot be observed under the color filter. Individuals can display red.

(3) Magnifying glass observation: Like the method of observing dyed jadeite, first, look for whether there are microcracks and whether the color distribution is concentrated in the cracks; Secondly, observe whether there is green dye in the thin part of the sample, whether the dye is filled in the pores of the particles, and whether the color is distributed in a network. Whether it is dyed green or purple, if the color distribution is from the edge to the center of the particle, it can prove to be evidence of dyeing. But when dyed purple, the real effect can only be seen by observing it under a white light tube.

(4) Visible light absorption spectrometer observation: Infrared spectrum can only solve the problem of whether there is resin in jadeite, so as to determine whether it is A goods or B goods, but it can't solve the problem of whether there is dye. The presence or absence of dyes can be detected through the observation of visible spectrometer. According to our identification experience for many years, the jadeite dyed green and treated with resin has a thick absorption band in the red region of visible light spectrum, which is not easy to observe because it is close to the red fading end, so we must look at it very carefully. This is one of the methods to test jadeite dyed with glue.

(5) Fluorescence observation under ultraviolet lamp: For the green-dyed and glued jadeite, there is still fluorescence under ultraviolet lamp, but the fluorescence reaction changes from blue-green to green-blue, which is slightly different from the green-dyed and glued jadeite, so it can be distinguished by careful observation.

For jadeite dyed purple with resin, it shows blue-purple fluorescence under ultraviolet lamp, which is different from the fluorescence reaction of pure dyeing or pure resin. Emerald dyed red with resin is inert and has no fluorescence due to the addition of iron-containing dyes.

It is not difficult to detect B and B+ carbon jadeite by the above method. As for B jadeite filled with inorganic substances, some people did not appear in the market in large quantities during the experiment. As long as they know how to identify species, they can see through the above methods besides infrared spectroscopy.

Six, coating treatment

The value of jadeite depends on color and light transmittance, and many jadeites with good light transmittance are colorless. In order to get more profits, some unscrupulous businessmen cover the surface of jadeite with extremely thin green plastic to make it appear emerald green. Because of its superb technology, a layer of plastic film is plated on the colorless and transparent jade surface, which is thin and smooth and difficult to be found by naked eyes. With a spotlight flashlight perspective, you can also see emerald green, which once made some people flinch and fall for it. According to records, around 1990, many such camouflage products were found on the border between China and Myanmar, and the locals called them "jade in clothes". This was introduced to Chinese mainland by unscrupulous foreign businessmen. Because it has been exposed, it is relatively rare at present. The test method is as follows:

(1) shows strong pink-blue fluorescence under ultraviolet lamp, which is caused by surface plastic.

(2) Soaking in the solution, you can see that the surface is full of astringency, while the inside is completely colorless.

(3) Refractive index measurement: The refractive index measured by perspective method is the refractive index of resin, which is about 1.52 (the refractive index of jadeite is 1.66).

(4) Determination of specific gravity: The specific gravity deviation between coated jadeite and natural jadeite is very small, about 3.33 (due to the small proportion of thin layers on the color surface).

(5) The absorption spectrum measured by infrared spectrometer is similar to that of jadeite B, showing the absorption spectrum containing resin.

(6) Other methods: The burning smell can be smelled by hot needle method.