3 thoughts on “What are the simple ways to identify the authenticity of gold?”

  1. Dorothy

    The general method to identify the authenticity of these gold is to use nitric acid. If there is no reaction, it is mostly gold. However, there are also platinum (Platinum) and a few precious and rare metals that are not afraid of nitric acid, but people do not often contact such metals. There are many adulteration methods in placer gold, mainly including: (1) gold plating on brass, placer gold mixed with copper powder and pyrite; (2) Silver coated gold with silver powder; (3) Sand gold mixed with hearth dust. ● generally, the first type of adulterated placer gold can be preliminarily determined as long as it is burned with a rapid fire. If there are many black objects, it must be adulterated. If the tested placer gold is completely unchanged, it is real placer gold; Or point the grinding path with sand acid. If the grinding path changes or disappears, it is false gold. ● in the second type of false placer gold, because silver is not easy to be burnt and discolored, it can be cut to open the placer gold mass, and see whether there are white spots on the section under a magnifying glass. If there are, it is false placer gold; Or use nitric acid point grinding path, if there are white spots, it is mixed with silver placer gold. ● the third type of placer gold is the most deceptive because the hearth ash is not afraid of burning and acid. At this time, it is better to use aqua regia (a mixture of hydrochloric acid and nitric acid of 3:1) to point the grinding head. If the grinding path disappears, it is the real placer gold. If there are still obvious traces, it is the fake placer gold mixed with cylinder dust. ● there is a common formula for the identification of clear gold in cooked gold, that is: weigh the weight, look at the color, judge the rhyme, fold the soft and hard, and use the acid point. Since the density of gold is significantly higher than that of common metals such as copper, silver, lead and zinc, it is about twice as heavy as that of silver and copper of the same volume. If the object is gold, it has a heavy feeling. This is the "Gold Pendant hand" of people. On the contrary, it is light. ● gold has its unique golden yellow luster (except for low fineness). Pure gold will shine brightly under strong light, which is not available to other metals, including copper. ● gold with high fineness has no rhyme and elasticity when thrown on the ground, while gold with low fineness has a slightly brighter sound, while copper products have a loud sound when thrown on the ground. Therefore, according to the sound of percussion objects, we can help us distinguish common metals from gold. ● gold is characterized by good ductility and small hardness. Pure gold is flexible and flexible, while copper is laborious. Or use a pin (nails can also be used) to draw it. If the force is small and the trace is obvious, it is gold, while the force of copper is slightly larger and the trace is slightly worse. Soft and hard folding is only applicable to rings and gold wires, but it is more difficult for gold bars, gold coins and gold bricks. It is also very effective to judge the authenticity of gold by grinding head. It is only necessary to grind it in different directions of the tested object. If the colors of several grinding paths are obviously different, there is no doubt that it is adulterated. ● if you don't believe in the above-mentioned identification methods of mature gold, you can only use nitric acid to point, that is, use nitric acid to point its grinding path to determine its authenticity. ◆ identification of gold jewelry 1. When the genuine product is bent by hand, it is soft and easy to bend continuously. It is easy to straighten when it is pulled by hand, and there will be traces when it is drawn with a hard object 2. The gold ornaments throw on the floor to make a "pop" sound. The false sound is sharp and loud, and it jumps higher than the real gold 3. The true color is dark yellow, the excessive red is fake gold, and the light color is silver, aluminum and other mixed gold 4. The real one is heavier and the fake one is lighter 5. True fire does not change color, false fire does not resist fire, turns black purple, and is not bright 6. It is quenched into water after it is really red, and the color remains unchanged ◆ identification of gold and jade jewelry ● first pay attention to the gold content. In China, it is indicated by the words "full red", "full gold", "80%, 70%, 90% and 100%. Internationally, the" K "table is used to indicate the gold content. 24K is full gold, the content is about 99.6%, 22K is 91.3%, 20K is 83%, 18K is 75%, 14K is 58.3%, and 12K is 50%. ● identification of jade jewelry: real jade is very hard and wear-resistant. If there are cracks inside the jade, the quality is poor. If there are wrinkles on the surface and bubbles inside the fake jade, the weight is light, the hardness is small, and the sound is clear when knocking each other ◆ identification of rare gold jewelry: rare gold jewelry is an alloy made of copper as the main raw material and appropriate trace elements. It does not contain gold. Its appearance is 14-24k gold color. Its wear resistance is better than that of gold and its specific gravity is lighter than that of gold. Words such as c20k, c18k and c14k indicate that it is equivalent to 20K, 18K and 14k Gold color. The color is similar but the quality is not ◆ Archimedes judged whether the gold was genuine or not. King ashiro of sugura gave the goldsmith a piece of gold and asked him to make a crown. After the crown was made, the king felt a little light in his hand. He suspected that the goldsmith had adulterated the gold, but the goldsmith assured him with his head that he had not, and weighed it in person. The result was as heavy as the original gold. The king still had some doubts, but he could not provide evidence, so he called Archimedes and asked him to solve the problem. After returning home, Archimedes closed the door to thank the guests and thought hard, but he could not understand it. One day, his wife forced him to take a bath. When he jumped into the pool, the water overflowed from the pool. Archimedes heard the sound of flowing water, and his inspiration suddenly came out. He jumped out of the pool and rushed into the street without even wearing clothes, shouting: "ullega! Ullega!". Madam was really worried this time. She mumbled "really crazy, really crazy" and then chased out. The people on the street did not know what had happened, and they all followed behind. Originally, Archimedes found a solution to the crown problem by overflowing the bathtub: the same substance of the same mass should be soaked in the water, and the volume of the overflowing water should be the same. If the crown is put into water, the volume of the overflowing water should be the same as the volume of the same mass of gold nuggets, otherwise the crown must be adulterated. After running to the palace, Archie Weide immediately found a basin of water, and then found a piece of gold and a piece of silver of the same weight. He soaked them in the basin twice. The water overflowing from the silver was almost twice as much as that from the gold. Then he soaked the crown and the gold into the basin separately. The water overflowing from the crown was more than that from the gold. Obviously, the quality of the crown was not equal to that of the gold. The crown must have been adulterated. In the face of the iron facts, the goldsmith had to bow his head and admit that silver was indeed mixed in the crown. The annoying mystery of the crown was finally solved
    natural jadeite (commonly known as A-goods) is rich in color, commonly green, green white, white, brown red, light purple, light yellow, etc. the color is natural and uneven. After careful observation of the texture of high-grade jadeite, some small reflections can be seen when changing the direction, which is the characteristic of jadeite
    there are also various kinds of artificially processed Jadeites in the market, generally including bleaching filling treatment, dyeing treatment, bleaching filling and dyeing treatment, which are commonly known as jadeite B, C and B C
    it is not easy to identify the authenticity of jadeite. To determine whether it is genuine natural jadeite, ordinary consumers must go to an authoritative identification department for identification. There are about six criteria for evaluating jadeite: color, transparency, structure, flaw, crack, cutting and carving. At present, some stalls selling precious jade in the market are often mixed with some exquisite artificial jade. The reliable discrimination methods are: look, listen and test. See, mainly see the crystal transparency, real jade transparency is strong, grease luster; Listen, Zhenyu's voice is clear and crisp, on the contrary, it is dull and dumb; In the test, the real jade scratched on the glass, leaving scratches on the glass, while the jade itself was not damaged at all. Common fake jade include plastic, colored glass, marble, electrochromic fake jade, synthetic class made of jade powder, crystal and salt water, and other fake methods. The means of identification are different. Plastic is lighter than jade in texture and has poor hardness. It is generally easy to identify. Coloring is also easy to distinguish between work. As long as you get it under the light or sunlight, you will see many bubbles in the glass. It is difficult to distinguish the electric color fake jade. After electroplating, the inferior jade is plated with a beautiful emerald green appearance, which is easy to be mistaken for the real jade. At this time, we need to observe carefully. If there are some small cracks with green and blue on the top, it is fake jade. Because the plating will leave cracks, experts call it "spider claw". Some people also say that if the electrochromic fake jade is placed in hot oil, the plating color will fade and return to its original appearance. The synthetic jade made of jade powder, crystal and salt water is imitation dark Laokeng jade. The identification method is simple, that is, their specific gravity is different. The specific gravity of natural jade is 3.3-3.4, while that of synthetic jade is only 2.8. Weigh it with your hands or weigh it with a balance to distinguish the true from the false. The jade articles imitated by nitrates are whiter than jade. The ancients said, "the jade race is high." That is to say, white jade should be regarded as high-grade, just like nitrate. It can be seen that nitrate and jade are difficult to distinguish. However, truth and falsehood are different after all. In terms of color, the white of white jade is often bluish, and the pure white is rare. The nitrate is pure white. As far as the nature of jade is concerned, the jade is warm and delicate, like grease and cream. Although the nitrate is also warm and moist, it is hard to avoid stealing light. White jade is a natural product, and it is difficult to have a uniform constitution. It contains jade tendons and flowers. If the nitrate is made artificially, there is no such phenomenon. White jade has a solid texture and no bubbles can be found. No matter how well the nitrate is processed, there are often bubbles and air holes exposed. If you understand these, you will not regard nitrate products as jade
    (1) check the hardness
    the higher the fineness of silver jewelry, the softer the texture, and the cleaner the surface. Take the silver bracelet of about 60g as an example. If it is pulled by hand, it will open without elasticity, and its fineness is about 95%; If there is some elasticity, the fineness is about 80% ~ 90%; If the elasticity is large, the fineness is below 70%
    (2) look at the stubble
    cut or fold the silver jewelry to see the color of the stubble. If the ornaments are soft, the stubble is thick and soft, slightly reddish, and the fineness is about 95%; If it is hard to bend by hand, the stubble is white and gray, or slightly reddish, and the color is about 90%; If the hardness is large, the stubble is light red, yellow white or grayish, and the fineness is about 80%; If the bend is hard, the stubble is reddish, yellowish, and yellowish, and the fineness is about 70%; If the stubble lipstick is black, or yellow is black, the color is below 60%
    (3) silver medicine smearing test
    grind the silver jewelry on the touchstone to form a silver track (the same as the gold test), and smear it on the silver track with silver medicine (silver medicine is a soft mixture of silver powder and mercury). The quality of more silver medicine is high, the quality of less silver medicine is low, and the goods without silver medicine are fake
    (4) color discrimination method
    use eyesight to identify its fineness and authenticity. The jewelry with high quality looks white, delicate and glossy, and the manufacturer, shop number and other marks are printed on the jewelry; Low quality, slightly yellow color, rough workmanship; The color of fake silver jewelry is gray and not smooth
    (5) bending method
    hold the bending with your fingers, the high-quality soft and flexible, easy to bend and not easy to break; The bending of inferior quality is relatively hard, or it is barely folded, and some can not even be folded with fingers; The silver coated ones will crack after bending or knocking with a hammer; Fake ones can't stand bending and are easy to break
    (6) throwing method
    silver ornaments with high fineness are heavy and cannot jump high when thrown on the table, making a "pop" sound; The fake or low-quality ones are light, and they bounce very high when thrown on the table, making a relatively clear sound
    (7) nitric acid identification method
    drop nitric acid on the file mouth of silver jewelry with a glass rod, and the high color is Brown Beige, dull green or slightly green; The low color is dark green, even black
    in addition, when buying silver jewelry, you should select the quality from the following four aspects:
    (1) look at welding. Some silver ornaments are made by welding, so it is necessary to see whether the welding is clean and tidy, and whether there is false welding or open welding
    (2) viewing brightness. Pure plating color and strong brightness are required
    (3) look at the veneer. Be firm and correct
    (4) look at the claw. It is necessary to check whether the claw has burrs, whether it sticks hands, scrapes clothes, and whether it is convenient to wear
    gemstone identification can be divided into three aspects: ① naming a gemstone and determining what it is. ② Material classification and clear material properties. ③ Gemstone quality is divided. (1) Name of gemstone. For gemstone identification, the name can be determined by measuring the density and refractive index data of gemstones. For example, the measured gem density is 3.52 (± 0.01) g / cm ^ 3, the refractive index is 2.417, and the dispersion is o O44, combined with its high thermal conductivity, can be named diamond (diamond). If we also have data on the chemical composition and crystal structure of gems, the naming of gems will be more accurate and perfect. Based on the name of gemstone mineral species, the varieties are divided according to color or special light (cat's eye, starlight, color change and color change). For example, the varieties of beryl gemstone minerals classified by color are called green beryl (also called Emerald), blue beryl is called aquamarine, and colorless beryl is called transparent beryl. There are varieties of beryl with special light, such as beryl cat's eye and starlight beryl. Corundum is a variety name of gemstone mineral according to color. Corundum with special light property can be divided into starlight ruby, starlight sapphire, sapphire cat's eye, etc. (2) Material classification. Material classification and identification is one of the most difficult tasks for gemstone appraisers. Before naming a gemstone, you must first answer the following questions: ① is the gemstone natural or synthetic or artificial? ② Has the gemstone been dyed and coated? Has it been oiled or chemically treated? ③ Has the gemstone undergone heat treatment or color diffusion treatment? ④ Has the gemstone been irradiated and colored? ⑤ Are the cracks and holes on the surface of the gemstone manually filled? According to the properties of materials, we divide materials into two categories: gemstones and artificial products
    gemstones include: ① natural gemstones: substances completely formed by nature, which refer to natural mineral crystals that have not been affected by man, and are synonymous with "pure" and "natural". Including various natural materials. ② Optimizing gems (artificial processed gems): the quality of gems is natural. Through various new methods and means such as chemical, thermal, optical and high-energy ray radiation, the quality of gems can be improved to improve the value of gems. It is difficult to draw a line between natural gemstones and optimized gemstones after treatment due to different treatment methods and intensity. Artificial products include: ① synthetic gemstone: the product formed by crystallization under artificially controlled crystallization conditions by some artificial method. Its physical or chemical properties and crystal structure are basically consistent with the corresponding natural gemstone. Such as synthetic diamond, synthetic ruby and synthetic sapphire. ② Artificial stone: refers to all kinds of artificially grown crystals, whose chemical composition, physical properties and crystal structure have no natural contrast. This artificial stone is a imitation of a certain gemstone, such as artificial cubic alumina (ZrO2) of imitation diamond. Its hardness is high (8.5) and its optical effect is very similar to that of diamond. However, its chemical composition, physical properties and crystal structure are different from those of natural diamond, and there is no natural contrast. It can only be called artificial stone, not "synthetic gemstone". ③ Mosaic stone (also known as composite stone): mosaic stone refers to the combination of two or more crystalline or amorphous materials into products by unnatural methods through adhesives or other means. Its components can be divided into gemstones, other minerals and chemical substances. Mosaic stone entering the market: Emerald mosaic stone, ruby mosaic stone, etc. ④ Imitation products: use various materials: chemical, plastic, glass, artificial crystal and other materials to imitate the effect, appearance or color of natural gemstones and synthetic gemstones without their chemical, physical properties and crystal structure. There are both gemstone imitations and synthetic gemstone imitations. ⑤ Reconstituted products: artificial products made by melting, bonding or fusing gem raw materials into a whole. At present, all kinds of artificial products rush to the market one after another to identify various artificial products in order to ensure the acquisition of real gems. The task of gemstone mineralogy workers is quite heavy

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