Basic common sense to help you choose your favorite jade

Once the advent of the jade, its crystal clear texture, unique aura and colorful color deeply impressed the world. Its beauty, rarity and value make Cuiyu the crown of the king of jade, the identification of jade, and many more. Little is known, here is the basic knowledge about the identification of jade, only for everyone to buy jade jewelry, provide a reference.

Cui nature: When identifying jade raw materials and finished products, pay attention to the plaque-like interweaving structure of the polished spots on the polished surface. In the case of a jade, you can usually see two forms of jadeite vigilance. One is a slightly larger particle. Granular phenocrysts, and the other is fibrous crystals intertwined around the phenocrysts. Under normal circumstances, the phenocryst particles in the same jadeite are uniform in size and are top grade.

Stone flower: In a piece of jade, there are usually small clumps, and the white fibrous crystals with poor transparency are intertwined into stone flowers. This stone flower and plaque crystal, some plaque crystal transparent, some micro-transparent to opaque. Transparency is the top grade, micro-transparency is second, and opacity is the next product.

Color: The color of the jade is uneven. There are white, pink, oily, green, and green beans with green or dark green and black. There is a shady point on the green emerald. The whole body is transparent green and the emerald is the top grade. The whole body is transparent and the opaque crystal is the top grade, and the translucent is second.

Gloss: The emerald's luster is bright and translucent, polished and delicate, and has a soft, strong glass luster. Jadeite has a high density and a high refractive index; it sinks rapidly in tribromomethane, and nephrite is characterized by such characteristics as serpentine, grapevine, quartzite jade, etc., all suspended or floated in tribromomethane. Jade has a refractive index of 1.63 and a hardness of between 6.7 and 7.4.

Inclusion: The black minerals in the jade, the inclusions are mostly melted and combined, the edges of the particles are loose and cloudy, and the green is deeper around the black inclusions, "green goes with the black". The combination of minerals and jadeites in jade plays a role in the changes in chemical substances. A person with an ornament of green and black plaques, after long-term wear of direct contact with human skin, the color of the ink will change with the length of time, and will vary from person to person.

Strong water-holding: refers to a drop of water on the surface of the finished jadeite, the water droplets are raised higher, similar to a drop of water in the lotus leaf, dew on the tip of the grass. In short, the main identification characteristics of jadeite are: uneven color, prolonged green trend; strong glass luster with oil; plaque interweaving structure; cool feeling, the color does not change under the Charles mirror.

How to distinguish jadeite grade

A: Jadeite A refers to the natural, unfilled and added color of natural jade jade pieces called A goods.

B: If it is filled with (such as filled with high molecular polymer, etc.) into B goods; B goods are still mineral components are natural jade ingredients, the color is also natural, but the filling of the gum will affect its color after aging The degree of vividness affects the transparency, gloss, etc. of jadeite

C: If the additive processing is called C cargo; the mineral component of the C cargo is a natural jade component. At the same time, after filling and coloring, it is called B+C goods.

Emerald mineral

The composition minerals of jadeite are mainly jadeite in a single pyroxene cluster or other pyroxene minerals (such as chrome jadeite and omphacite) with high jadeite molecules (NaAISi206); the mineral composition of jadeite is considered to be high pressure and low temperature. The product of metamorphism and confirmed by the synthetic experiments of jade. If NaAI in jadeite is replaced by Ca, Mg, Fe, Ct, etc., it will be beyond the scope of English components, and become other pyroxene, (English, omphacite, diopside, neolith, etc.) diopside The jadeite composed of neon and so on is also called "Gemstone Jade" but it does not belong to jade jade.

For the identification of jade jadeite, the national standard "GB/T16553-1966 jewellery and jade identification" has made more accurate regulations. However, the jadeite in business is larger than the jadeite jade. However, since jadeite is a polycrystalline aggregate, the mineral component of the jadeite and jadeite types is determined. The more accurate method is the electronic probe image component analysis, but it is limited by the instrument and equipment, and the quicker and more convenient method is the differential end oil immersion method. As long as a common polarizing microscope and a few bottles of refractive index immersion oil, the sample obtained is very small, even if the high-grade ring face does not affect its beauty and value.

Emerald color

Emerald green is the treasure of jade, and the green-green perspective is the top grade, and there is a jargon saying that “the color is ten times higher than the price”. Therefore, the jade color technology continues to innovate. In addition to the red and purple colors, only the green varieties are added, and at least four types are seen on the market. The value of natural emerald green jade is only one to one thousandth of A goods, even lower than B goods. The colorless jade is dyed into a bright green jade to pretend to sell high-grade jade, which causes some consumers to suffer large losses and mental burden.

Early jadeite with chrome salt added color, observed in the Charles filter into red, (natural green calcium aluminum garnet jade also red), a batch of chromium salt dyed hard jade ring face, as early as 1956, the American Gemological Institute found . Nowadays, many dyed jadeites do not use chromium salts. The characteristics under the look-up mirror are similar to those of natural jadeite, and the stability is also good. Therefore, the check filter can only be used as a reference. In the past, dyed jade, the color level precipitated in the network column, and now some green jade colors (including some B+C ornaments or flakes) have not seen this phenomenon, so there is no colorant precipitation in the crack. The traces of this, since this is not necessarily the A goods. In recent years, a jade bracelet and pendants with unevenly dyed light green color are common on the market, pretending to be sold as natural jade. This kind of jewelry, soft color, a certain transparency (referring to water) is not glued, the 437nm absorption line under the beam splitter is clear, the knocking sound, the ultraviolet fluorescence characteristics, the Charles filter observation, are basically the same as the natural jade, the retail of this bracelet The price is generally between 500 and 1500, which is more popular with the general working class and tourists. According to the data of many tests, a dye (partially polished chrome powder) is used to fill the microporous slit. Due to the reflection of the light, the jadeite of the dyed part is light green. Dyeing has overall dyeing, some of which are directly burned, and some are accompanied by purple (also known as "spring color" which is a multiple dyeing method). It is a special variety of bracelets with several sections of pale green lavender.

If it is soaked in a solvent such as a detergent (add ultrasonic cleaning if necessary), most of the dye can be washed off, but after washing, people will leave a faint green color. The micro-stained dark green silk in the pores can be seen with a 10x magnifying glass (obviously even with the naked eye). After dyeing and washing, the color is lighter, but more like natural, there is a greater deception, the average consumer is difficult to identify, some bosses with certain business experience also see a point into a batch of goods, they are fooled, then It is inevitable to pass on to consumers, which is also a frequent occurrence. Even if the professional jewelry inspection staff is slightly negligent, it is possible to issue this dyed jade as a natural jade test report.