It is feasible to find gold in rivers, but it is difficult to find older rivers and purify them through chemical procedures. The cost of purification alone is greater than the value of gold itself, not to mention the time cost. Gold is a simple form of chemical element gold (Au), which is a soft, golden yellow and corrosion-resistant precious metal. Gold is a rarer, more precious and more valuable metal. Generally speaking, the gold in the world is in ounces. In ancient China, gold was measured in ounces, which was a very important metal. It is not only a special currency for reserve and investment, but also an important material for jewelry industry, electronics industry, modern communication and aerospace industry. The chemical symbol of gold is Au, and the financial English code is XAU or gold. The name Au comes from a story of Aurora, the goddess of dawn in Roman mythology, which means shining dawn. Pay attention to the purchase of gold: First, choose a brand enterprise with good reputation, and don't be greedy for cheap and choose a brand-free vendor. The price of gold is relatively transparent, so beware of being significantly lower than the market price;

Secondly, when buying gold products, remember to ask for invoices, which is the core of protecting consumers' rights and interests;

Third, if in doubt, you can find it in time. The gold jewelry testing institutions under the national technical supervision department are located in major cities, which makes it easier to detect the composition of gold jewelry.

Fourth, choose to invest in gold products such as gold bars and nuggets, and choose regular merchants who promise to buy back, and the quality can be guaranteed.

The testing standards of gold products in China are very strict, and the supervision of regular merchants from raw material purchase to storage to processing and sales is generally standardized. The sales of investment gold bars of major brands and channels in China can generally be repurchased, but they must be damaged when repurchased, then sprayed with a musket, and the gold bars become "golden bumps", and then detected by gold detection equipment. If there is any problem, you will know.

Moreover, the production process of gold bars is actually relatively simple, and there will be no technical problems, but the gold jewelry process is more complicated. A few enterprises may dispute the fineness of gold on minor issues such as solder joints, but it is not a problem of adulteration, so consumers need not worry.

Professional appraisal institutions generally appraise gold and silver products in two ways, one is nondestructive testing, that is, physical methods such as spectroscopy do not cause any appearance impact on the products; The second is destructive test, which uses chemical methods to identify substances extracted from commercial slices. China requires 990‰ pure gold, 999‰ pure gold and even 999.9‰ high pure gold.

9999 gold must be identified by chemical methods, and the rest can be identified by physical methods. Because "there is no shortage of gold", no matter how high the purity is, gold bars and ornaments contain impurities. Therefore, as long as the gold content reaches the standard, the state does not clearly stipulate whether the impurities contain elements such as tungsten and iridium. It does not mean that gold bars containing elements such as tungsten and iridium are unqualified. The key depends on the final gold content.

Even if gold bars and ornaments contain tungsten and iridium with a density similar to that of gold, appraisal institutions can still conduct appraisal by professional chemical means, and it is not difficult to detect them.

One of the reasons for the spots on jewelry may be that the content of gold jewelry is problematic. It may be that the iron filings attached to gold are oxidized and rusted, and the color becomes darker, but it is not fake. With the intensification of industrialization, in the process of processing gold jewelry, it is inevitable to come into contact with iron tools, and some iron filings may be brought into gold products. We can see this clearly under the microscope. People can take it to the gold shop and ask Master to help them burn it, otherwise it will rust after a long time.

Note that if it is something containing mercury, including cosmetics for ladies, some brands of baby shower gel will directly or indirectly lead to discoloration of gold jewelry.

"Whether it is pure gold or K gold jewelry, there are obvious marks on it, which is stipulated by national standards." According to the regulations of the industrial and commercial department, precious metal jewelry should be marked with the origin, manufacturer, material and content, and products without the mark are unqualified products. If there is a quality problem, the quality inspection agency can give detection and judgment according to the imprint. Consumers should buy their own brands and gold ornaments with different gold contents according to the imprint.

Finally, it should be reminded that gold jewelry itself is a consumer product, not an investment product. Its price already includes processing, loss, consumption tax and other expenses. At the time of discount, all merchants will calculate the price of gold raw materials, and there will be losses in the process of repurchase, so we should invest carefully.