Make clear the manufacturer and color by naked eye observation. On the surface of gold jewelry, there should be signs of regular brand manufacturers and alloy purity (fineness) and clear and delicate words. If the jewelry has no seal, or the imprint is rough and fuzzy, it is necessary to doubt the reliability of gold jewelry. Check and change the color. Gold should be bright red and yellow, with lasting color and high purity, the color of the United States. On the other hand, if the purity is not enough, as long as it contains 0.0 1% copper or silver, the color will be slightly purple or greenish white, that is to say, "seven greens, eight yellows and reds 1995." The so-called fake gold jewelry in other metals can be identified by its color. Ear speech recognition module. Jewelry falls naturally from a height. If it just clicks and the color is low and inelastic, then the fineness of gold is very high. If the sound is crisp and elastic, it means that its color is not high, and the jewelry contains more metal components such as copper. The freehand weighing method is heavier. The easiest way is to weigh by hand. As the saying goes, gold is "pressed out by hand" because other metals such as copper are heavier than the same volume of gold. The specific gravity of gold is 19.3, which is higher than that of silver, copper, aluminum, tin and other metals. The weight ratio of gold to silver is 1.2 times that of copper, and the weight ratio of 40% heavier than that of aluminum is the same volume. Other metals can be identified as fake gold ornaments because of their heavy weight. Recognize biting the gold medal. Gold has low hardness and is relatively soft. It can be bitten by teeth, and there will be other metal traces that do not have this feature. In addition, the higher the fineness of gold jewelry, the softer it is. You can also check the fineness by bending. If the fineness is low and there is more silver in it, the copper is not easy to bend. This method can distinguish whether gold ornaments are shoddy or not. Lick the truth of knowledge. In your mouth, gold licks with your tongue for a while, then it smokes and has no smell. If it is gold, if there is a little sweetness, it is a bronze medal. Law of fire and water. As the saying goes, "fire and water are incompatible", but gold is indifferent to fire. If possible, you can use the "fire and water solution" to see the true face of jewelry. Authenticity of fire awareness. "Real gold is not afraid of fire." After being cooled by high-temperature and fire-resistant jewelry, if you still have yellow, it will not be deformed, compared with yellow; If it turns black, it is a counterfeit product made of other metals. To determine the authenticity of nitric acid. Nitrate jewelry, if gold is safe, it will not change; If it is copper, there will be green smoke. In addition, there are some old gold jewelry. It used to be not very pure. Mix a little silver and copper more or less together, even a little (sometimes the surface is green), you can put it in water, dilute it with nitric acid 1 times, heat it for half an hour, take out the jewelry, and then remove the water. Then the surfaces of silver and copper are removed. If nitric acid only needs to add some salt, if there is, there will be white precipitate immediately, that is to say, in silver jewelry. Please rest assured that this treatment will not damage your gold jewelry, and the reverse color of the jewelry will be more beautiful. Sharp eyes, ears, weighing hands, biting hands, licking hands (in order to know when bait is better than precision), adding the authenticity of "fire and water solution" and the basic quality of gold jewelry will all be displayed in front of the world.