The Study Of Applying The Petrological And Mineralogical Characteristics To Commercial Grading And Appraising Of Jadeite Jade

Jadeite Jade, as a kind of Jade with high quality, has many excellent gemological characteristic, such as gorgeous and changefully color, the tightness and the hardness of its texture, beautiful luster and transparence, and good toughness. Those characteristics attribute to its petrological and mineralogical characteristics.The color-causing of Jadeite Jade is complex and of varieties. Its color can be divided into original color and secondary color. The report, from the mineral and chemical components to the ultraviolet-visible-near infrared absorption spectrum, analysed the color-causing mechanism of multicolor. Many minerals show colors, and the green of Jadeite is due to appropriate quantity of Cr³⁺, which is the main reason of high-quality green. It is very difficulty to appraise the color's quality, because of the various changes. A systemic way is suggested for appraisement, from the appearance to the 3 elements of color, i.e. from the amount, distributing, uniformity to the tone, saturation, brightness, and include the causing of color.Jadeite Jade is a special kind of metamorphite, and its texture is changeful, because of multistage metamorphism. The texture is one of crucial factors of Jade's quality. It directly influence the transparence and its beauty, and the transparence can mirror the color. All that make the jade more beauty. As for the texture, the elements to be studied includes the granular size, the shape, the contact relation each other and the orientation of minerals. The report advanced a way, from the macroscopic to micrographic characteristics, to appraise the texture.The final aim of appraisement is to guide market. This text, acording to the color and the texture, discussed how to appraise and valuate Jadeite Jade at length. The commercial speciality of Jadeite Jade, the decisive factor of its value, and the market of Jade are analysed synthetically. The difficulty in evaluation of Jade is put forward. And some Jadeite Jade are appraised and valuated in the end, which include various kind and various grade.