Jade's "Old Pit New Pit" Problem

Jade's "Old Pit New Pit" Problem

As for the old pit jade, everyone must see more, but to be honest, it is generally seen in the product label and product description. If I want to help me find a "new pit" of jade, then it will be difficult for me to be a friend! It is also strange to say that the jade of the new pit is not available in the Chinese market. ! Are you selling abroad?

In fact, it is around us! But how do you define whether the old pit is jade? Long story! The world-famous high-quality jade deposit is located in the Wuyou River (the tributary of the pro-Dunjiang River) in northern Myanmar. From the thirteenth century (and perhaps early), alluvial sands and glacier sands were mined in this area, and the original jade deposits were not discovered until the eighteenth century. Native jadeite minerals are found in serpentine petrified peridotite extending from north to east in the Precambrian strata. The main producing areas are the treks, the violent, the pan and the Nan Na.

The four mining areas are long and thick, consisting of veins, lenticular and rock-like jadeite ore bodies that are close to each other, and are nearly 1-2.5 km long along the strike. The veins containing jadeite are in the form of an annulus-like structure. The central part of the vein is a jadeite single mineral emerald rock, which gradually changes to the albite-a jadeite belt, azhotite belt and alkaline amphibolite belt toward the vein wall. Emerald rock is generally 2.5-3 meters thick and is mainly composed of white jadeite. This jadeite is a dense (very fine to medium) aggregate of jadeite particles, which looks like white granulated marble (careful observation of the interwoven structure). In some places, spots and bands of various colors (dark green, apple green, yellow-green, and pink) are scattered on the white "ground", and sometimes several colors in the same emerald rock are properly blended and matched. When these mining areas were discovered, some of the ore in the veins had been exposed to the open air for a very long time. Due to the long-term soaking and erosion of the local acid-laden groundwater and rainwater, the local jadeite ore becomes finer in texture (because the coarse-grained ore has been weathered and corroded) and it shows a very good pass after processing. Permeability, the jade produced in these mining areas is called "old pit" by insiders.

The so-called "new pit" refers to the pits where the jadeite veins formed later, away from the above-mentioned veins. Because of the younger age, the open-air formation time is not enough, so most of the texture is rough, the water head is short, and some people also add the jadeite ore, but in fact most of the "new pit" jade ore is from the tens of meters deep Lie out! The most representative one is the jadeite vein called "83 pit" by insiders. Because it was discovered later (1983), and the output is quite large, the raw materials used to make jade jewelry are mainly from that mining area. The real old pit deposit has been exhausted due to the excavation of several generations.

Where the old pit minerals are generally close in texture, the density can generally reach 3.20 (due to the occurrence of the banding phenomenon in the process of mineral formation, the mineral content of the fusion is also different, and the jadeite rock with different density will be produced, but the average density should not be Less than 3.20/cm2), and the new pit minerals may not have the high temperature and pressure at the time of production. As a result, most of the texture is coarse, although the texture is finer, it looks like a good variety of heads, but the density is generally Can not reach the limit of 3.2. Because of its coarse texture, some are like winter melon, and some are like radish. Their background color is mostly white, gray and light green. The ore looks like coarse salt is pressed together. The background color is often scattered with green, dark green, and dark green. The shape of the color generally shows cloud-like, dip-like, vein-like, clump-like, scattered and messy like floating flowers. It’s really hard to be elegant, but it’s a shame to abandon it! Therefore, a powerful industry army that optimized and improved it was born.

Now all the foundations on the market are exquisite, and the jade with good head is called the old pit.