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 piece of 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.
The first thing is to know the difference between jade and stone. Stone is most easily confused with jade. The stone is artificially smelted, with loose structure and even green. Although it is deliberately uneven, it is unnatural. The broken part of the stone is bright, easy to wear and lose its light. The stones are light, and some have bubbles. Emerald is a natural mineral with compact structure and uneven green color, but it is natural, green and bubble-free. The broken part of jadeite is ballast, which has great hardness and weight.
The second is to know how to identify colored jadeite. Put the colored jadeite in nitric acid or sulfuric acid, and the green will fade after several hours. Put the colored jadeite on the iron at 70~80℃, and the green will fade after a few hours. These two characteristics can be used to distinguish colored jadeite from natural jadeite.
Third, we should know the difference between jade and green natural minerals: the green of natural minerals that are easily confused with jade is not as bright as jade, and their characteristics are different, such as jasper, most of which have black spots and the black spots are triangular. Australian stone, blue with blue head, impure color. Green agate, green flashing blue, uniform color, but turbid. Dongling stone, green flashing blue, flashing gray, with a small white star shining on the surface.
In addition, spectroscope is a key tool to distinguish dyed jadeite from natural green jadeite.
Teach you how to distinguish the quality of jadeite;
Emerald has won the reputation of the king of jade with its luxurious, deep and steady character and irreplaceable advantages. Its advantages and disadvantages should be viewed from four aspects: color, transparency, shape and impurities.
Color-color is an important link to determine its value. The color should be rich and even, and it must be positive.
Transparency-good jadeite has good transparency, fine texture, green and dark green with transparency, such as clear spring water, luster and good moisture.
Shape-the shape, size and thickness of jadeite should be appropriate, and the grinding thickness should be uniform.
Impurity-whether the texture is clean or not and whether it contains impurities determines the quality of jadeite. Emerald can't have black spots, spots, cracks and flower marks.
Emerald a, b and c goods
In jade trading, the definitions of jadeite A, B and C goods have been recognized: unfilled and colored natural jadeite jade pieces are called A goods. If it is filled (such as filled with high molecular polymer, etc.). ), just call B goods; The mineral composition of B goods is natural jadeite, and the color is natural, but aging with glue will affect the brightness, transparency and luster of the color. If it is colored, it is called c goods; The mineral composition of C goods is the composition of natural jadeite. If it is filled and colored at the same time, it is called B+C goods.
1. The color of jade
Emerald jade is regarded as a treasure, and it is said that "the price of color is ten times higher". Therefore, the coloring technology of jadeite is constantly innovating. In addition to adding red and purple, only add green varieties. Dyeing colorless jadeite into brilliant green jadeite and selling it as high-grade jadeite have caused great losses and mental burdens to some consumers. In the past, colorants were deposited in the network cracks of dyed jadeites, but now some jadeites dyed green (including some B+C ornaments or pieces) can no longer see this phenomenon, so the colorants deposited in the cracks are not necessarily A goods. In recent years, a kind of jade bracelet and pendant with uneven light green dyeing is common in the market and sold as natural jade. This kind of jewelry has a soft color, a certain transparency (water), no glue injection and knocking sound, which is basically the same as natural jade. The retail price of this bracelet is generally 500- 1500 yuan, which is quite popular with the working class and tourists. According to the data of many tests, the pores are filled with a dye, and the dyed jadeite is light green as a whole due to the reflection of light. Some are dyed as a whole, some are only dyed locally, and some are accompanied by purple (also known as "spring scenery"), which makes a bracelet present a special light green and lavender. The dark green filaments impregnated in the micropores can be seen with a magnifying glass with a magnification of 10 (obviously visible even with naked eyes). Dyed and washed, the color is lighter, but it is more like nature and more deceptive; Not only is it difficult for ordinary consumers to identify, but some bosses with certain business experience have not seen the doubts and entered this kind of jewelry in batches.
2. About "Emerald"
Some experts believe that the important feature of natural jadeite is "emerald" (commonly known as "flying wing"), that is, the crystal flash phenomenon in jadeite is the flash of mineral crystal face. Microcrystalline jadeite is generally invisible, so it cannot be used as a characteristic symbol of natural jadeite.
3. Knocking sound
The knocking sound cannot be used as the basis for judging jadeite A and B goods. Some jade sellers often bump lightly with two bracelets, making a crisp "steel" sound, indicating that it is natural jade, and the obvious impact sound of jade B is slightly dull. However, it is not necessarily natural jadeites that make a "steel" sound, such as diopside (such as Qinghai jadeite) and amphibole sodium jade (such as Myanmar "Shuimozi" jade). At present, some B goods appearing on the market can also make a crisp "steel" sound.
Step 4 mesh
Emerald rinsed with strong acid generally has obvious pores and network structure. Stress and weathering in natural jadeite can produce obvious pores and reticular structures, which are often difficult to distinguish from reticular cracks caused by acid corrosion. The view that "people who observe cracks, pits and pits must be B goods" may not be appropriate. Therefore, the author suggests removing the concept of "glue-free B goods". The natural pores of jadeite can be filled with zeolite and clay minerals in the later stage; Mineral powder or polishing powder can also be filled in the process of cutting, grinding and polishing. These fillers are not B goods and are easy to identify.
5. Class B goods
Some articles think that the filler of goods B is epoxy resin. Wu Shuntian et al. (1995) pointed out that the common jadeite B filler in the market is a resin similar to opticon, and other compounds such as phosphophthalic acid are also found. Organic polymer is a complex system; The traditional wax filling treatment is generally considered not to be B goods, but it is still regarded as A goods. However, Wu Shuntian and others believe that most of the wax filling should belong to B goods. This opinion should be considered, because some porous jadeites are similar in visual effect to jadeites filled with colloidal wax, which is also deceptive.
6. Classification of jadeite grades
On the premise that the jadeite jade pieces identified must be natural jadeite, the grade and price grade are classified according to the 5C2T standard: composition, color, clarity, cut, weight (carat), transparency and structure] (generally, it is not necessary to classify the works into B goods and C goods). Jadeite is the crown of jade, and high-grade jadeite constantly creates amazing sky-high prices in various auctions, so counterfeit products such as B and C, which are fake natural jadeite, emerge in an endless stream, causing headaches for genuine merchants, consumers and inspectors.
Wearing fake ancient jade is harmful to health.
A lady bought a Yu Pei that was said to have been unearthed in an antique market a few days ago. The lady saw from the book that the ancient jade must be close to the body and rubbed, so the color will become more and more beautiful, so she wore a string and hung it around her neck. Unexpectedly, after a while, she felt pain and itching in her chest. At first glance, the skin in contact with "ancient jade" is red, swollen and peeling, and jade is dull instead of moist. Experts believe that this is a fake ancient jade that has been chemically treated. Buying such fakes will not only cause economic losses, but also be harmful to health.
It is understood that fake ancient jade is rampant in the antique market at present. Counterfeiters often use chemical etching to make ancient jade look guqin. These chemical reagents are usually strong acids such as hydrofluoric acid, nitric acid, sulfuric acid and hydrochloric acid. After finishing the Qin color and gray skin of fake ancient jade, the surface is coated with floor paint, crystal paint and epoxy resin. , causing the illusion that bright and moist gray skin penetrates into jade. Experts remind the public that long-term contact and friction between human skin and such fake ancient jade may cause redness, tingling, itching and molting. Faced with all kinds of fake ancient jade, collectors should be careful!
Attachment: Maintenance of Emerald
The chemical properties of jadeite are very stable, so it is relatively simple and easy to maintain. "Jade raises people, and people raise jade". The more jade you wear, the more beautiful it is. Wearing jade often is the best maintenance for jade. Daily maintenance, just wash with water to remove dirt, and then dry it with a clean and soft cloth; It is best to wear or take it off in a safe place such as sofa and carpet; Wear jade pendant, pay attention to check whether the red rope and necklace are firm, and replace them immediately if they are damaged.