Why does jadeite have cracks

Jade "has nine rows in ten", so how do the cracks on jade materials naturally form? Let's talk about it in detail:

Emerald was originally formed by vein jade, that is, large ore belt. With the geological movement and the erosion of groundwater, these ore belts are constantly broken and surfaced with the crustal uplift. When vein jade (rock jade) is exposed to the surface, with the surface weathering and water erosion, rock jade is constantly broken into small pieces. Some of these small jadeites are constantly washed away in running water, constantly colliding with other stones in the river bed, and their soft parts are constantly falling off. Finally, the jadeite core is weathered out of the cortex, which we call water stone. Therefore, the cracks in water stones are mostly formed by collision, and the cracks are slender and deep, and rarely staggered. There are few small cracks around the cracks. Generally speaking, we think that water stone is a better jadeite screened by weathering, and all varieties are relatively old. Therefore, if the finished product has solitary lines to avoid cracks, few cracks are bifurcated, and there are no staggered cracks and cow hair cracks around it, then combined with other characteristics, it can still be recognized that this jade species is old enough. Then another part of the fallen jadeite jade block was washed away by the flood and piled up, and finally the mountain gravel was formed through the lifting movement. At present, the old materials of various famous sites are mostly alpine gravel jadeite. Cracks formed in high mountain gravel are completely different from water stones. Except for some mechanical impact cracking accidents caused by falling from a height, most cracks in alpine gravel materials are caused by internal thermal expansion and cold contraction. Due to the poor heat conduction effect of jadeite, the outer layer is often heated to a high temperature by sunlight during the day, and the inner layer is still cold. When the inner layer warms up at night, the outer layer gets cold again. Under the constant thermal expansion and cold contraction, the shell of jadeite appears tiny cracks, and then the shell falls off layer by layer; In the interior of jadeite, the loosely interwoven parts of fibers are pulled out of cracks due to pulling, and the cracks are constantly expanding. Therefore, when the jadeite is tender, we usually see all kinds of cracks, such as cross cracks, chicken feet cracks, parallel or staggered small cracks, and sometimes there are as many cow hairs (cow hair cracks), which leads to the whole material being unable to receive materials. Reflected in the finished product, a large number of techniques such as crack avoidance, hollowing out and through carving are often used to make up for the defects of the material.

Of course, in the process of transportation and processing, improper methods will also form cracks. Crack is a serious defect in jadeite, which has a great influence on the value of jadeite.