The crystal coffin is cool and has jade-like anti-corrosion function, which is conducive to prolonging the preservation time of the body; Moreover, the crystal coffin itself is corrosion-resistant, especially its transparency, which is both beautiful and convenient to appreciate. This may be the main reason why people value crystal coffins. However, under the same natural conditions, the advantages of crystal coffins in anti-corrosion are not so good, and they are much inferior to those of China's specialty-golden nanmu coffins. Many uncorrupted body discovered in archaeology are almost all made of nanmu. I mentioned a short story in "The History of Grave Robbery in China": A bowl of braised pork was put into a coffin made in the south, and one month after it was transported to the north, the meat was not only rotten, but also not cold. Since nanmu coffins are so good, why do national leaders still favor crystal coffins? Mainly out of respect. Compared with nanmu coffin, the production cost of crystal coffin is too high. To make a good crystal coffin, you must first have high-quality raw materials-at least first-class crystals. Crystal is actually a kind of high-grade glass, and its main component is silicon dioxide. However, in the jewelry market, crystal is a kind of gem, which was called "water essence" and "water jade" by the ancients in China. From this name, you can see that crystal is extraordinary. In many cases, the value of crystal can be comparable to that of jade. However, it should be noted that not all crystals are crystal clear, because they contain different elements and are also colorful, including black, yellow, purple, green, gray, rose and so on. But the most popular crystal is colorless and transparent, which is also the most basic impression of crystal. Crystal coffins are all made of this transparent crystal.