High school politics class when talking about a topic "gold and silver is not a natural currency, but the natural currency is gold and silver." Gold and silver are nothing but two rare metals in nature. They are not money in and of themselves. Money is a historical category, as early as before the emergence of money there is gold and silver, so gold and silver is not a natural currency. When the development of commodity trading to the equivalent of the gradual reunification of the time, the responsibility of the general equivalent of natural fall naturally gold and silver body, this is because the value of a small piece of gold and silver is very high, inanimate, easy to segment, easy to carry and identify fineness, with Many take advantage of general equivalents. When the general equivalent is fixed on gold and silver, money is produced. When gold and silver are used as money to be used, the "identification of fineness" has become a very important step. It is easy to understand, if you sell someone else a commodity, received the purity of gold and silver is not enough, that is a loss of it! Therefore, "to verify the precious metal content of gold and silver coins" for the purpose, in most European countries have been implemented for hundreds of years of precious metals identification and control. Gold and silver In addition to this precious metal material used as money, but also often used for jewelry, silverware and watches. Therefore, for this category of items, the state will be included in the scope of identification and control. This is why we can see the imprint on the precious metal replica watches uk. Common imprint a total of four, namely: "Precious Metal Impression of the Country" "Precious metal purity mark" "Joint Control of Precious Metals" "Factory standard, imprint of responsibility" In the above piece of Rolex Yacht 2 case back cover, respectively, have been identified. (Forgive my garbage shooting ability, will be made into a stainless steel). Precious metal purity imprint As we all know, gold is soft. Although this metal can be made of case, clasp, but it is easy to damage. So now in addition to some of the brand in order to gimmick will use pure gold to produce outside, almost all of the brands are used in gold as the main alloy material. In this alloy material, the most popular is 75% gold and 25% of the mixture of other metals. Such a proportion of alloy material, known as "750" or "18K". These two figures represent the gold alloy is the ratio of 750 per thousand, or 18/24. From left to right are 18k gold, 18k red gold, 18k white gold, and PT950 platinum 75% of the mixture of gold will be due to other types of metals and the rolex replica proportion of different colors and hardness. The other 25% of the other metals in 18k white gold are generally nickel, silver, palladium, manganese, etc., the addition of these metals can make the color of gold into white. The 18k red gold color source is mainly metal "copper", people have become accustomed to use different numbers to define the color change, 3N red gold (composition of 75% pure gold, 13% silver, 12% copper) 4N red gold (75% pure gold, 9% silver, 16% copper), 5N red gold (composition 75% gold, 4.5% silver, 20.5% copper). You can see, the less the added silver and more copper, the color is also more reddish. So sometimes, we can see in some brands of imprint processing, in addition to representatives of the purity of 750, there are 18k gold on behalf of its use of the ratio of "N coefficient." It is noteworthy that, 18K red gold because of the brand, the origin of the different and different. Even the same brand with the same watch also has a slight color, because the production of alloy will be batch problems, can not guarantee exactly the same. 18k gold, 18k red gold, 18k white gold, the general mark of the mark is "750" or "18K". The noble platinum is an exception, it is marked "PT950". PT is the abbreviation of "Platinum Platinum", 950 is the meaning of purity. Precious metals of the country Identification and control of precious metals, each country is different. They are each using their own precious metal control regulations, with independent sampling, testing, marking and technical requirements. Because we are talking about rolex replica watches, so this time we mainly talk about watches and clocks, "Switzerland" precious metal imprint. Switzerland now uses the official name of the precious metal seal "head of a St. Bernhard dog", the Chinese translation called "St. Bernard's head." Prior to 1995, Switzerland asked to mark the precious metal watch to distinguish between different raw materials. Gold watch need to be marked "queen" picture, and the use of silver need to be marked "duck" stamp. After 1995, Switzerland modified the standard on the use of precious metals imprinted, as long as the precious metals (gold, silver, platinum, palladium) watches are covered in the case of "St. Bernard dog." Many watch friends to see the "St. Bernard dog" is thought to be gold, but in fact 4 dollars a gram of silver is also considered "expensive" metal. For the "St. Bernard's head," the imprint is not casually covered. In Switzerland, it is fully protected by law. "St. Bernard 's head" mark has been strictly limited, even the size is no exception. A total of two "St. Bernard dog", a large dog, the size is 2 mm wide, 1.6 mm high, the other is a puppy, the size is 1 mm wide, 0.8 mm wide. In Switzerland, the detection of precious metals is carried out by the following offices and offices of the Federal Customs Service. At present they have a total of 40 detectors, responsible for more than 1 million each year of precious metal items detection, assessment. In order to divide responsibilities, each subordinate office of the dog head seal is a nuances. In the magnification of the magnification, we can clearly see the "St. Bernard dog" mark the lower right corner there is a letter "G". The "G" represents the "Geneva Geneva" office where the precious metal was inspected and identified for this case. Above is the identification of branches around Switzerland, the abbreviation of the code, interested friends can take a magnifying glass to see their high-power watch where the certification is. Prior to this, "St. Bernard 's head" imprint of the seal are hand carved, very fine. Covering the precious metal, we can see the obvious bump changes, even the dog tongue and hair can be identified. Fake precious metal stamps often can not be so realistic, so many friends rely on stamps to identify the true and false watches. But in the past few years, there has been a new imprint to add the way - laser engraving. This "St. Bernard dog head" mark has appeared in the Omega, Piaget, celebrities and other brands on top. The depth of its carving is very shallow, it is easy to wear out. At the same time, because it is made of laser, which greatly increased the risk of counterfeiting. At present, there are in the country after the buckle and other precious metal attachments, and then marked with this laser version of the "St. Bernard dog" posing as the real thing. The risk factor is large, do not know how the Swiss guys think. Since the difficulty of people down to forge! In addition, the "St. Bernard dog head" mark is not dedicated to the Swiss production of precious metal watches. In addition to Switzerland, countries and regions in the Swiss watch sales have to go for testing and assessment. Joint control of the precious metal imprint Light Switzerland's precious metal imprint has been enough trouble, there are many countries in Europe. All of these national technical and legal requirements hinder cross-border trade in precious metal products. After a lengthy discussion in the 1960s, the Convention on the Control and Marking of Precious Metal Products (abbreviated as "Hallmark Convention" or "Vienna Convention") was signed in Vienna in November 1972 and entered into force in 1975. In this contract, countries reached an agreement with a fair balance to mark the precious metals. The above figures represent the purity of precious metals, while the balance of the frame represents the different types of precious metals. Such as platinum is the prismatic frame, gold is the two overlapping circles. Factory standard, the responsibility of the mark In addition to the need for national and inter-national levels of the watch on the precious metal materials to monitor and control, the original producers are also within the scope of supervision. The original producer of the precious metal material needs to apply for a "Responsibility Mark" in Berne's Precious Metals Central Control Office in Berne, Switzerland, which translates "Responsibility Mark" or "RM". Common "imprint of responsibility" is this, shape from the use of metal processing "anvil" or "hammer" frame, which sets a number. Different figures on behalf of different manufacturers. More troublesome is that because the shape and appearance of the "imprint of responsibility" has almost no restrictions, as long as it does not and official signs, other registered imprint of responsibility, registered trademark or brand name or international organization abbreviation similar or identical. So in real life, we can find a variety of "imprint of responsibility." Unless you are the industry's old drivers, or simply can not remember exactly which factory produced the shell, clasp, strap. In addition to those wonderful shape of the "responsibility mark", some watch brands have been able to produce their own shell and other precious metal accessories, so they often use the obvious brand logo "factory standard" to apply for their own "responsibility mark. For example, the above "responsibility mark" is from the "Rolex", and the brand's trademark almost the crown, as long as a little bit of common sense of clocks and watches friends will be able to recognize it. For the "imprint of responsibility", Switzerland's management is also very strict. Once applied, "imprint of responsibility" can not be changed within 20 years, in case someone changes frequently to cause misunderstanding. Even if the ownership of the plant is transferred to a production company, the responsibility is transferred to Berne's Central Office of Precious Metals for change. Once a problem, you can quickly find the person in charge directly. There is a big story behind the imprint of a little precious metal, in addition to the story, the imprint of my faithful in terms of the watch there is a certain role. Such as through the integrity of the imprint to speculate whether the watch has been polished, watch the true and false ..... Note that this term is referred to as "speculative" rather than deterministic. Precious metal stamp of the clock because of the time span is too long, too many countries involved, and most of the hand-stamped cover, but also a new true watch mark blurred, overlap stamped cover situation, so the result can not rely on imprint to determine a Watch the state and true and false.