The price of gold 999 is 489 yuan to 5 10 yuan per gram. As the price of gold is still rising, its price is not very stable, but is constantly floating. : 1 .9999 What do you mean by pure gold? Nine thousand nine hundred and ninety-nine pure gold means that the gold content is not less than 99.99%, which is called ten thousand pure gold. The number of gold symbols indicates its purity. For example, 999 is 1000 gold, that is, 999 of 1000 gold, and 9,999 is 10000 gold, which is higher, that is, nine thousand nine hundred and ninety-nine of 10000 gold, with a difference of 9/ 100. 2. What does hard gold mean? Hard gold refers to physical gold, but it is "hard" gold made by a new method. Its texture is harder than ordinary gold. Also known as "thousands of feet Hard Gold". Adding 0.005% special metal to increase its hardness, so as to achieve the corresponding hardness. Hard gold is hardened by a special process and tempered by fire to become ordinary gold. Because of different technologies, the price will be more expensive. 3. The difference between 9,999 gold and 999 gold is the purity of 9,999 gold and 999 gold: 999 is 99.9% gold and 9,999 is 99.99% gold. The number of gold symbols represents its purity. 999 is 1000 gold, and gold is 999 per thousand. 99.99 is 10,000 pieces of gold, which means that the purity of gold is 99.9 million pieces, with a difference of 9,000 pieces. Among gold ornaments, the most common one is pure gold 999, because the material of gold is soft. Many gold ornaments use non-gold materials such as joints and buckles, which make the ornaments stronger, so the overall purity will be reduced, and it is difficult to achieve pure gold of 9999. Generally speaking, gold bars or some simple designs are pure gold 9999. And from August 20 17, the new national standard stipulates that thousands of gold and ten thousand gold are called "pure gold", and the content of pure gold must be greater than or equal to 99%. Therefore, in terms of gold ornaments, the difference between the two is not too big, which has little effect on the later recovery of old gold. There is no need to discuss these differences too much. In fact, for the jewelry we wear, 999 gold is enough, both in color, purity and craftsmanship have reached the highest level of jewelry. For headwear, 99.9% is the highest, because it needs welding. It is said that headdresses are deceptive, and gold bars are generally 9,999. Now the state stipulates that all gold ornaments should be marked with gold and gold, collectively referred to as gold. 4. Reasons for the formation of gold: About 2.6 billion years ago, in Archean, volcanic eruption sent a large amount of gold from the core to the mantle and crust along the fault zone, and the original gold source was formed through marine deposition and regional metamorphism. About 654.38 billion years ago, in Mesozoic, due to the strong external force, the crust was deformed and folded out of the sea, and the gold material was activated and intensively migrated, forming a gold mining area, which is what we call rock gold. In areas rich in rock gold resources, a large amount of natural gold is often left after rock oxidation. After tens of millions of years of weathering and erosion, shallow rock gold has become sand. Due to the stability of gold, it dissociates into monomers, and in the process of river transportation, it is deposited in the stable water of the river due to its large specific gravity, thus forming placer gold deposits. According to Tiangong in Ming Dynasty and Song Dynasty, there are about 100 gold producing areas in China, so it is difficult to list them one by one. Among the rocks, the big one is called horseshoe gold, the middle one is called olive gold and crotch gold, and the small one is called melon seed gold. The big ones produced in water and sand are called gold nuggets, and the small ones are called wheat bran or McKinley. Those who dig wells on the flat land are called Jinsha, and those who dig wells on the flat land are called Doujin. But it must be washed and melted before it can become a whole piece of gold.