Inlaid jewelry is a major category of jewelry. At present, there are two kinds of jewelry inlaid with precious stones in the market. One kind is natural gems, such as jadeite, diamond, ruby, emerald, cat's eye, sapphire and so on. , or jade diamond jewelry, is a precious ornament. Another kind of artificial gem, such as artificial diamond, artificial cat's eye and artificial ruby. The biggest difference between natural gemstones and artificial gem is that the former is pure in color, while the latter is gorgeous but light in color; The former will never fade, while the latter will fade with time. At present, synthetic gemstone technology can be confused with real gemstones, and it is almost the same as natural gemstones in color, transparency, optics and physical phenomena. For example, synthetic diamonds, synthetic corundum and precious stones, which are common in the domestic market, are also very expensive. However, synthetic gems can still be distinguished by experience. The biggest difference is that synthetic gems are almost flawless, natural gems have some flaws, and natural gems have growth lines. According to the crystal growth line, the authenticity can be distinguished. The growth lines of natural gemstones are regularly arranged along the direction of hexagonal crystal shape, so parallel straight lines can be carefully observed inside the gemstone, sometimes obvious, visible to the naked eye, and sometimes hidden, which need to be set off with paper and then carefully observed with a magnifying glass. The growth line of synthetic gemstones is round. You can also tell from the appearance. Synthetic gems, whether the color of the sun, the transparency or the performance of gem stars, are obviously too regular and lack natural traces. On the other hand, natural gemstones glow from the inside, and their colors are pure and deep. The value of natural gemstones is extremely high, and the price of synthetic gemstones is also very high. You should go to a jewelry store to buy inlaid jewelry. As for the so-called inlaid jewelry copied by street vendors with glass, plastic and other materials, it has no value, just a decorative toy.
Identification method of silver jewelry
People buy silver jewelry mainly for dressing up; As a gift to relatives and friends; Personal wealth preservation.
How to judge the greatness of silver jewelry? Many people have been cheated on this issue. Silver jewelry has the following main characteristics, which we can judge according to.
In terms of specific gravity, the specific gravity of silver is 10.5, which is much larger than other silvery white metals or alloys. For example, the specific gravity of lead is only 2.7.
Judging from the sound, silver is soft, and the sound made by throwing it on a hard object is very weak, while the sound made by other metals is very clear.
Judging from the color, the white of other metals is different from silvery white after all, especially after combustion and cooling. After barbecue with fire, if it is real silver, the silver will remain unchanged; If it is fake silver, or a product with poor quality, it will turn black after barbecue. Another method is to drop nitric acid on the surface of silverware ornaments, and after wiping off the nitric acid, the surface of the ornaments is still silvery white, indicating that the silver content is quite high; If it is an ornament with low silver content, it will be grayish black.
First, check the tag. According to the national standard GB 1 187-8P, the silver content is not less than 925‰, which is called 925 silver and marked as 925 silver. If the silver content is not less than 990‰, it should be weighed and stamped with silver seal or 990 silver.
Secondly, the higher the purity, the whiter the silver, the finer the surface, the even luster and the touch-up. If it contains lead, the surface is blue-gray; If it contains copper, the surface is rough and dry. There is "black rust" on the surface of silver oxide forbidden tube, but the color is black and bright, while lead, tin and copper are dull.
Because the density of silver is slightly higher than that of ordinary metals, generally speaking, "aluminum is light, silver is heavy, and copper is neither light nor heavy." So we can preliminarily judge whether it is silver by weighing. In addition, the hardness of silver is lower than that of copper, but higher than that of lead and tin, so it can be tested by slightly scraping the surface of an object with a pin. If there are traces but not obvious, it can be preliminarily judged as silver jewelry.
As for Wei Zaiyin, which is common in the market, Manager Zhao said that Wei Zaiyin is generally made of copper, lead, tin and aluminum. Its characteristics are: the appearance of white copper is gray, the stubble is brick gray, and it is green rust; Lead is gray-blue, soft and can be marked with nails; Tin is silvery white and soft; Aluminum is white gray, soft in texture and light in specific gravity.
How to identify jadeite?
Collection and appreciation of jadeite and identification of A, B and C goods
First, Burmese jade is also called jadeite. It was very popular in the late Qing Dynasty and the early Republic of China: for example, a jade spirit tube by Rong Lu, Minister of the Interior of the Qing Dynasty, was worth two gold coins. In the mid-1930s, Yu Wang Tie Yuting in Beijing had a bracelet, which was sold to Du in Shanghai for silver. Myanmar jadeite is bright and clean because of its high hardness. Moreover, good Japanese colors are bright and peaceful, with high preservation and collection value, so they are called "the king of jade". It is loved by many people who love and wear jade. Japanese benzene? New Zealand also regards jade as its "national stone". Due to the special geographical relationship that jadeite is produced in Myanmar, which is close to China, and most of the finished products are processed in China, and the special preference of China people for jadeite, western countries generally consider jadeite as China's "national jade".
Second, the color of Burmese jadeite. Due to different regional customs, the color of Burmese jadeite is slightly different. In the jade kingdom of Myanmar, jadeite can be divided into three categories, with a grade of 12. The domestic jewelry industry divides jadeite into more than 30 grades according to its color. Generally speaking, the tones of Burmese jade can be roughly divided into the following six types.
1, white. Basically does not contain other impurity elements.
2, red. The chemical element containing iron < FC3 > is commonly known as iron.
3. green. < Cr > containing more than bivalent chromium
4, black. Contains more than two chromium and iron.
5, purple. Containing the elements chromium, iron and cobalt
In particular, the green color in Burmese jade can be worn regardless of status, status, age and gender, except for its bright color and excellent durability. Therefore, it conforms to the implicit, peaceful, Wen Ya and cordial character of China people. The social demand is growing day by day. Prices have also doubled or even hundredfold. At present, the price of a jade bracelet in the international market has reached 10 million yuan. Even Myanmar jadeite ornaments with slightly inferior jadeite color are expensive as long as they are genuine A goods with sufficient water head, clear technology and harmonious colors.
Third, the quality and identification knowledge of Burmese jadeite. No matter from the mineral resources or mining capacity of Burmese jade, good jadeite is very limited, so some speculators and mercenary businessmen "take advantage of it". A large number of fake and fake goods, profit from it. Even in the emerald kingdom of Myanmar, fakes abound; Fake stones and ornaments can be seen everywhere.
At present, there are four kinds of Burmese jade popular in the market, according to the level of authenticity:
A goods are both natural texture and natural color. The identification method mainly focuses on the following three points:
(1) Look before you leap. Due to the relationship between mineral resources and mining volume and the specific conditions of large demand, there are few good Burmese jadeites on the market at present. In particular, there are few varieties with green color and bright ground color.
(2) Generally, varieties such as Mabel Miao, spinach green, scarlet or violet floating flowers are common.
(3) Observed by naked eyes under the light, the texture is delicate, the color is soft and the stone lines are obvious; Slight impact, crisp and pleasant voice; Holding it in your hand has a heavy feeling, which is obviously different from other parts of the stone.
Goods B will have jadeite with black spots, commonly known as "dirty". Use strong acid to soak and corrode to remove dirt and cotton to increase transparency, and then use high pressure to inject epoxy resin into the microcracks caused by strong acid corrosion to fill the cracks.
(1) The color of B goods was good at first. If you look closely, the color will become evil. If you look at it under a lamp, the color transparency will be weakened.
(2) Within two years, B goods gradually lost their luster, were full of cracks and became ugly. This is caused by strong acid forcing its original quality.
(3) The density is reduced and the weight is reduced. Slight impact, low voice, lost the crisp sound of a cargo.
C the goods are completely artificially colored.
(1) At first glance, the color is not right and evil.
(2) Looking closely under the lamp, the color does not naturally exist in jadeite crystals, but is filled in the cracks of minerals, showing a network distribution of colorless roots.
(3) Observing with Charles filter, the green color becomes red or colorless.
(4) The surface color can be removed by scrubbing with powerful decoloring agent or turned brown.
D goods, D goods pretending to be jade ornaments mainly have the following two categories.
(1) jade. That is, other jadeites pretend to be jadeites. There are mainly Thai jadeite and Luxi jadeite, Nanyang dushan jade jadeite, Qinghai jadeite, Miyu jadeite, Australian jadeite and Dongling stone. The differences between the jadeite mentioned above and Burmese jadeite are as follows: First, the hardness is low; Second, low density (light weight) and weak luster.
(2) Green glass and green plastic. Most of these substitutes are dull and ugly, and their luster is very weak. The relative density is very light, the hardness is low (it can be carved with nails), and there is no cold feeling.
Identification of diamonds
Perspective test —— Clean the gemstone cut by round diamond, put it on a piece of white paper, draw a line on the paper, and judge whether the gemstone is a diamond by observing the line on the paper. If it is a standard round cut diamond, the lines on the paper cannot be seen through the diamond (synthetic strontium titanate and synthetic rutile are similar to diamonds and have no perspective effect). However, due to the different refractive indices of most imitations, there is indeed enough light leaking from the pavilion surface, and some lines on the paper can be seen through perspective observation.
Brightness estimation-the ability of external reflection and total internal reflection of gem crown to refract light, which is called brightness. When diamonds and their imitations are placed in the same light source and environment, almost all the light entering from the crown is reflected by the crown when viewed from the top, showing a strong brightness. However, the imitation is different from the diamond in refractive index and cut, and the light entering from the crown will leak out from the pavilion to varying degrees, thus reducing the brightness.
Oiliness test-Draw a line on the diamond table with a special pen or ballpoint pen dipped in oily ink, which will leave an uninterrupted straight line. However, other imitations are not lipophilic, leaving intermittent dotted lines at the scribe line.
In the water drop test, clean the diamond and the imitation table, drop a little water each, and observe the time and contour of the water drop. The water droplets on the diamond will remain spherical for a long time, while the water droplets on the imitation will disperse in a relatively short time.
Breath test-put the sample to be tested and the known diamond sample together on the glass, blow on them and observe the disappearance of the fog. The fog on the diamond will soon disappear, while the fog on the imitation will slowly disappear.
Sensory test-When the tip of your tongue touches the diamond and its imitation at room temperature, the diamond is much cooler than the imitation.
instrument identification
Magnification detection-observation under a magnifying glass or gem microscope. (1) Diamonds generally contain a small amount of fine mineral inclusions in addition to their extremely high quality. Common inclusions include: black graphite, brown spinel, red chrome spinel, garnet and colorless transparent stone. (2) Due to the scarcity, preciousness and high hardness of diamonds, the cutting and polishing of diamonds are very particular, and the cutting ratio, crown angle and pavilion angle of diamonds are all calculated. The table and facet of the diamond are straight and there is no warping phenomenon. The edges and corners are straight and sharp, and three or more edges strictly intersect at one point, while imitations are often smooth because of their low hardness and poor cutting. (3) The extremely high hardness of diamond makes it difficult to be worn, even if the wear is limited to the edges and corners of a single facet. However, due to the low hardness, the facet edges are often rough after wear.
Thermal conductivity meter test-Thermal conductivity meter can quickly, simply and accurately identify diamonds and their imitations, especially for the identification of diamond jewelry. Different substances have different thermal conductivities, and the thermal conductivity of diamond is the best among gems (the thermal conductivity is 1000 ~ 2600 W/m℃). Touch the probe of the thermal conductivity meter to the sample, turn on the power supply, and you can know the real greatness of the diamond according to the heat transfer speed of the thermocouple, the light number displayed by the LED or the text displayed by the LCD.
Test of reflector-The advantages and disadvantages of reflector and thermal conductivity meter are just complementary, that is, gems that are easily confused on thermal conductivity meter can be clearly distinguished on reflector, while gems with similar characteristics on reflector can be clearly distinguished by thermal conductivity meter.
X-ray fluorometer test-the application of X-ray in gem identification is very important. X-rays belong to high-energy rays, which will cause lattice damage and change the color of gems. This identification method is generally not used.
Electronic balance or other weighing instruments-It is a very effective and simple method to distinguish between rough stone and imitation diamond by using electronic balance or other weighing instruments. The density of diamond (3.529g/cm3) is quite different from that of most imitations, and only the density of natural topaz (3.56g/cm3) is similar to that of diamond.
The difference between diamonds and imitations
The difference between a diamond and a natural colorless gem-the gem most similar to a diamond is zircon, because colorless zircon also has a large refractive index and dispersion, and the processed zircon also has a radiant appearance, so it is one of the best natural substitutes for diamonds. The difference between diamond and zircon is actually very simple. Diamonds are equiaxed gems without polarization and birefringence, while zircon has polarization and large birefringence. Looking down at the edge of its pavilion from its crown, you will find that one edge has become two, that is, there is a "ghost" phenomenon, and the diamond is still an edge. In addition, it is easy to distinguish by hardness method. Just carve an artificial sapphire on the gem to be identified. If the mark can be drawn, it is a diamond; If it slips and cannot be scratched, it is not a diamond. Other natural colorless gems, because of their low refractive index, are difficult to have a "radiant" and "colorful" appearance even after good cutting and polishing. The refractive index of diamond is 2.42, which is beyond the reading range of general refractometer. The refractive index of ordinary gems is easy to measure, such as colorless topaz and crystal (if other features are similar to diamonds, the refractive index is generally not measured to avoid scratching the refractometer). In addition, the processing of general gemstones is often not strict, and light leakage often occurs, while slightly larger diamonds (such as more than 30 points) are often strictly processed and generally do not leak light because of their high value.
The difference between diamond and artificial imitation diamond-another imitation most similar to diamond is cubic oxidation milling, abbreviated as CZ. Because this synthetic gem was first developed by the Soviets and is very similar to diamonds, many people call it "Soviet diamond" (it is worth noting that some people think that Soviet diamonds are fake, but in fact the Soviet Union is also a country rich in natural diamond resources). Cubic zirconia belongs to the equiaxed crystal system, with hardness as high as 8.5 and large refractive index and dispersion. Processed "Soviet diamonds" also have the attractive appearance of sparkling fire, and sometimes their "beauty" even exceeds that of general poorly processed natural diamonds. It is not difficult to distinguish natural diamonds from other artificial imitation diamonds. (1) The hardness of all synthetic products is less than 9. For gems without inlays, the hardness score can be used to distinguish them. Diamonds can carve artificial sapphires, but not diamonds. This method can also effectively distinguish some glass imitations with coated surfaces. (2) The colors of artificial substitutes are generally "white" and clean, while natural diamonds have some yellow tones except some high-grade products with 96 colors and above VVS, and some "flaws" can be seen. (3) Synthetic substitutes have low hardness and low price, so the processing is rough, and the ground gems often have "light leakage", "burr" or rounded edges.
The difference between diamonds and synthetic diamonds, color-changing diamonds and sandwich diamonds-The third kind of counterfeit diamonds are synthetic diamonds, which often have almost the same physical properties as natural diamonds, such as hardness, refractive index and dispersion. They can't be distinguished only by the senses. A simpler distinction is that synthetic diamonds usually contain some metallic mineral inclusions, which are "magnetic", while natural diamonds do not. The method is: put a magnet in front of the microphone and move the diamond quickly in front of the microphone. Synthetic diamonds make tiny noises, indicating that they are magnetic. The discoloration of diamonds was discovered at the beginning of this century after the radioactivity of radium was discovered. Colored diamond with good color is more valuable than colorless diamonds, which promotes the development of turning light brown or yellowish diamonds into colored diamond. It is necessary to distinguish between natural diamonds and colored diamonds. Looking down from the mesa of artificial colored diamond (produced by radiation or bombardment of high-energy accelerator), there will be some umbrella-shaped color circles or shadows, and there will be a characteristic absorption line of 594nm in the absorption spectrum. In addition, its fluorescence, radioactivity and conductivity are also different from those of natural colored diamonds. Sandwich diamonds are mainly due to the special shape of raw materials. Craftsmen often "splice" two originally smaller diamonds into a larger diamond, while others make a double-layer diamond with a diamond as the top and a crystal or colorless synthetic corundum as the bottom, and cover the bottom with a "golden claw" or "Phnom Penh" to deceive. For this kind of diamond, we can carefully observe whether there is a bonding interface inside the diamond, and often we can see some small bubbles and glue, or we can feel a layer of fog on a certain level inside the diamond. If the gem is not inlaid, it will be better to observe it in diiodomethane or clear water.
The difference between diamond and coated diamond-the fourth kind of fake, coated diamond may be the most advanced imitation on the market at present, which is produced by combining high pressure with chemical vapor deposition. This synthetic diamond has low cost and simple conditions. When the coating thickness of this synthetic diamond is greater than 10 micron, it has similar reaction with natural diamond when measured by "thermal conductivity meter". However, this substitute is still flawed. First, the coating surface is small diamond polycrystal, and the general appearance is gray. Second, the ratio of coated diamonds to natural diamonds is different, which is the key to identification.
Discrimination between true and false crystals
Discrimination between true and false crystals
★ See:
In the process of crystal formation, it is often influenced by the environment and always contains some impurities. When observing the sun, we can see weak, even and tiny cracks (ice cracks) and catkin-like substances (cotton). Fake crystals are mostly made of inferior crystal slag and glass slag. After polishing, coloring and imitation, there are no cotton and ice cracks.
★ Lick your tongue:
Even in the dog days of hot summer, it feels cool to lick the surface of rock crystal with your tongue. Fake crystals are not.
★ Lighting:
Rock crystal stands upright in the sun, and it radiates beautiful luster from any angle. Fake crystals are not.
★ Hardness:
The hardness of the crystal is very high, so scratch the jewelry with gravel, leaving no trace; If there are streaks, it is a fake crystal.
★ Check with a polarizer:
Turning 360 degrees under the polarizer, the rock crystal changes in four brightness and four darkness, and the pseudocrystal does not change.
★ Check in two colors:
Natural amethyst has dichroism, while fake amethyst does not.
★ Test with thermal conductivity meter:
When the thermal conductivity meter is set to 4 squares of green test gemstones, the rock crystal can rise to 2 squares of yellow, while the false crystal does not rise, and it rises to 1 square yellow when the area is large.
Distinguish jadeite ornaments
The festival is close to the tourism market and enters the peak season. Middle-and high-grade jadeites with good species, water and color are entering ordinary families as mainstream ornaments. Because of their beautiful colors, profound implications, auspicious symbols and rich cultural heritage, some trace elements contained in them can regulate the microcirculation of the wearer. According to industry estimates, the demand for high-grade jadeite jewelry in China market will increase tenfold in the next five years. Holiday tourist season has always been the peak season for jade ornaments. Please Guanyin, buy the zodiac, seek good luck and please. However, in recent years, many consumers have been complaining that there are serious quality problems in the jade jewelry they bought when traveling abroad during the holidays. To this end, how do consumers identify?
According to experts from Shanghai Gemstone Association, jadeites on the market are divided into three types: A, B and C according to whether they have been chemically treated or not. A, a natural jadeite without any chemical treatment, is more precious. Goods B are jadeite treated by artificial pickling and bleaching, and then filled with oxygen resin, while goods C are jadeite dyed artificially. Because commodities B and C are bright after treatment, some dishonest merchants often pretend to be commodities A. ..
Experts advise consumers to master several tricks when buying. First, recognize the logo of the goods. The jadeite of A goods is usually directly labeled as "jade", while the jadeite of B goods must be labeled as "jade (treatment)" according to national standards, and the jadeite of C goods must be labeled as "jade (dyeing)". It is best not to buy jadeite without the above logo or unclear logo. Second, merchants are required to issue formal invoices, stating the quality of jadeite. For high-priced goods above 5,000 yuan, you can ask the merchants for quality inspection certificates; Third, look for well-known brands. At present, Zhang Tiejun Jade, Laojiao Jinjiutian Jade, Yayi Jade City, Laofengxiang, Yuyuan Shopping Mall Huabaolou, Times Zhenshen Jade Street, etc. can guarantee the quality and only sell one piece of jade.
How to tell whether pearls are true or false?
Nowadays, the pearl market is becoming more and more incomprehensible, and the craft beads are so perfect that people can hardly respect them. In Beihai, Hainan and other tourist attractions, some vendors often chase after tourists, and there are many ornaments that look like clear water beads in the handicraft market. If the craft beads are wrapped in plastic film, they are easy to identify. The two beads are polished straight and smooth, and each bead is circled, just like it is made in a mold, and a layer of skin falls off when scraped. However, it is more difficult to identify some craft beads with shells as the core and coated with pigments. Some beads are even machined into the shape of various lines of freshwater beads by lathe, and they are just like real ones after being wiped off, only a little "real". So, what key issues should be grasped when identifying natural or cultured pearls?
Look at the luster of pearls of different origins first. The halo reflected from the surface or inner nacre can't be different. As the saying goes, "pearl" needs to be carefully tasted in combination with the real thing. Pearlescence is mainly reflected from the fine structure layer inside the pearl, which is a unique luster produced by light diffraction. This luster can be observed in dark light without direct light, which is similar to observing the growth line and inner handle of a gem under a dark-field gem microscope, reflecting the thickness of the nacre, and is particularly clear under weak light irradiation. The light reflected by weak plastic is "thief bright", while the coating process of carbon material is deceptive to some extent, so it should be carefully identified.
Second, observe the surface characteristics of pearls. The number of surface defects of pearls directly affects the beauty of pearls, but there are few pearls without defects. The different defects of each pearl are just different from the birthmarks of other pearls, which provides a basis for the identification of Wei Zhen. The surface defects of pearls are defects or stripes. When a foreign body invades between nacreous layers, a defect will be raised on the surface. Sometimes it is necessary to observe carefully with a magnifying glass of 10 times, and some banded phenomena will always be found.
Third, touching Zhu Wei with your hands is greasy, and the pearls are refreshing, which makes it cool and pleasant to hang around your neck.
Fourth, try to grind with teeth or two beads. As mentioned above, plastic beads will slip when grinding, but grinding pearls along the peak of teeth will have a sense of sand. If it is a good bead, this kind of sand feeling is particularly uniform, and the feeling is simply wonderful. This is because the crystals that make up the nacre are arranged in an orderly way, just like the roof panel, which is called shingle arrangement in jargon, so rubbing it will make people feel like sand.
5. When trying to burn with fire, flame appeared in Zhu Wei, black smoke appeared on the burning surface, and the bead layer on the surface fell off. No black smoke color was found on the burning surface of the pearl, and the surface layer was intact without falling off. As for the choice of pearls, first of all, it should be clear that freshwater pearls and seawater pearls belong to two different grades of goods, just like jade and jade, which cannot be compared. When choosing the same kind of beads, we should consider its color, luster and mother-of-pearl layer thickness, and consider its color, luster, mother-of-pearl layer thickness, shape defects (spots) and other factors to make our final choice.