How is jade jewelry formed? There are many magical legends in the folk. Geologists have always regarded it as a mystery. Some people think that jadeite, like diamonds, is formed by crystals formed under high temperature conditions of several thousand degrees deep in the earth’s crust, but it is not. Many geophysicists in the United States have done a lot of simulation experiments in the laboratory, and combined with the actual situation of jade deposits found around the world, they believe that jadeite is not formed under high temperature conditions, but is extremely high under low temperature conditions. Deformed under pressure. What are the processes that need to be experienced in the formation of jade?
Professor Ichikawa Ichiro of Tohoku University in Japan, in the book “Gem”, specifically pointed out that jade is formed at 10,000 atmospheres and relatively low temperatures (200-300 ° C). We know that the earth is from the surface to the deep, and the deeper the temperature, the higher the pressure. However, jadeite is crystallized under low temperature and high pressure conditions. Of course, it is impossible to be in a deeper part. So where does the high pressure come from?
This high pressure is due to the squeezing force caused by the movement of the earth’s crust. It has been confirmed that all areas with a distribution of jade deposits are areas with strong crustal movement.
There is another factor: igneous rock intrusions (medium-basic rocks) containing albite in places where jadeite is found. The chemical composition of albite is NaAlSi3O8, so it can be inferred that jadeite is formed by desiliconization of rocks containing sodium feldspar under low temperature and high pressure conditions.
In order to become a special jadeite-emerald, the following conditions must be met: the emerald surrounding rock must be high-magnesium, high-calcium and low-iron rock. The jadeite produced in this environment is purer and less iron makes the bottom not gray. Despite the low iron, there is still iron. To make the jade pure and impurity-free, it must be produced under strong reducing conditions, that is, in a reducing environment. Because in the anoxic environment, the Fe contained in it will form magnetite and precipitate, instead of entering the jade lattice, the emerald green can be corrected. In addition, there must be geological effects after the formation of jade and many strong hydrothermal activities, and the jadeite will be transformed into a green jade, a good water, and a pure jade. The jade color forming process is carried out along with the hydrothermal activity and is a color forming process with different intensities. Moreover, the coloring element slowly decomposed into chromium ions should be at 150-300 ° C for a long time, and the optimum temperature is about 212 ° C. The chromium ions can enter the crystal lattice uniformly and uninterrupted, and the jadeite generated under such conditions The green color is very uniform. After the complete generation of super jade, there is no large geological tectonic movement, otherwise there will be cracks of different sizes and directions, which will affect the quality. It is difficult to have all of the above conditions at the same time, which is why the special jadeite jade is rare.