1. Fill the cup with water (know the total volume v of water), and hang the platinum in the cup with a thin thread until it is completely immersed and taken out. 2. See how much water is left in the cup, the volume is V-V 1, then the volume of platinum is (V-V 1). 3. The weight of platinum is M 4, the density of platinum is = the annual output of platinum is only one twentieth of that of gold, and it takes five months to extract one ounce of platinum from 10 ton platinum mine. Domestic platinum jewelry usually contains 90% pure platinum and is marked with "Pt900". Platinum has a natural white luster and will not fade after long-term wear. The hardness of platinum makes it the best friend of diamonds. 1898, platinum was widely used in jewelry. French Louis Corthie once said: "Platinum is the king of precious metals." Kardi, who came to the gem world as the king of gems, caused a global platinum wave with his extensive use of platinum, and established the impression that "the best jewelry should use platinum". Why is platinum called the king of precious metals? Corthie noticed that platinum is so sticky that even a small inlay can firmly support the gem. The smaller the inlay, the more people can see the gem clearly, and will not show extra colors on the gem like gold. Although platinum will melt in aqua regia (a mixed liquid formed by concentrated nitric acid and concentrated hydrochloric acid), it is completely unaffected by anything else. Nor will it deteriorate like gold meets mercury. This lasting and elegant white light is the reason why it is called the king of precious metals and is chosen as a wedding ring by people. Platinum with high purity is represented by PT, and platinum used as jewelry is mainly PT900 and PT850. This means that they contain 90% and 85% platinum respectively. In Japan, a PT less than 850 is not called platinum. The purity of 18K gold is 75%, which shows that the purity of platinum is high. In Britain, only those above PT950 are marked as platinum. However, even if the inside of the ring is engraved with the mark of PT900, its quality cannot be guaranteed. Consciously store ornaments are engraved with government inspection marks. In addition, some stores have unique quality assurance marks engraved on their ornaments, so consumers should go to these reputable stores to buy them. Platinum Platinum is a natural white precious metal. The annual output of platinum is only one twentieth of that of gold, and it takes five months to extract one ounce of platinum from 10 ton platinum ore. Domestic platinum jewelry usually contains 90% pure platinum and is marked with "Pt900". Platinum has a natural white luster and will not fade after long-term wear. The hardness of platinum makes it the best friend of diamonds. 1898, platinum was widely used in jewelry. French Louis Corthie once said: "Platinum is the king of precious metals." Kardi, who came to the gem world as the king of gems, caused a global platinum wave with his extensive use of platinum, and established the impression that "the best jewelry should use platinum". Why is platinum called the king of precious metals? Corthie noticed that platinum is so sticky that even a small inlay can firmly support the gem. The smaller the inlay, the more people can see the gem clearly, and will not show extra colors on the gem like gold. Although platinum will melt in aqua regia (a mixed liquid formed by concentrated nitric acid and concentrated hydrochloric acid), it is completely unaffected by anything else. Nor will it deteriorate like gold meets mercury. This lasting and elegant white light is the reason why it is called the king of precious metals and is chosen as a wedding ring by people. Platinum with high purity is represented by PT, and platinum used as jewelry is mainly PT900 and PT850. This means that they contain 90% and 85% platinum respectively. In Japan, a PT less than 850 is not called platinum. The purity of 18K gold is 75%, which shows that the purity of platinum is high. In Britain, only those above PT950 are marked as platinum. However, even if the inside of the ring is engraved with the mark of PT900, its quality cannot be guaranteed. Consciously store ornaments are engraved with government inspection marks. In addition, some stores have unique quality assurance marks engraved on their ornaments, so consumers should go to these reputable stores to buy them.