Abstract: Zhongis a property of jadeite,which affects the value of the jadeite products.The concept of"Zhong"of jadeite is an important and basic problem in the field of the jadeite gemmology.It is a pity that mainstream gemmologists or gem researchers have the different visions and disagree against each other.To sum up,the experts and scholars have three types of visions on the definition of the"Zhong"of jadeite.The first,"Zhong"of jadeite refers to the transparency of jadeite.The high transparency of jadeite refers to good"Zhong",and bad"Zhong"refers to low transparency of jadeite.The second,"Zhong"of jadeite refers to the structure.The fine structure stands for good"Zhong",while the coarse structure stands for bad"Zhong".Thirdly,"Zhong"of jadeite refers to the species or varieties of jadeite,such as,the species like glass and ice,coarse grain,green silk and so on.They are commonly pictographically described,such as jadeite like glass is called glass species,jadeite like taro is called the taro species,and jadeite like ceramic is referred to ceramic species.
However, these three views are not exact, which have caused confusion to jadeite beginners and fans, as well as a bad effect on the criterion of jadeite grading evaluation and a negative impact on the valuation of jadeite.
The concept of jadeite is defined in the paper. "Zhong"is the synthesis of hardness and compact degree of jadeite, and also is the combination of the grinding resistance, polishing performance and brightness (shine). The "Zhong"of jadeite with high brightness (shine),good grinding and polishing performance, high hardness, as well as high compact degree, is regarded as good or old "Zhong". On the contrary, "Zhong" of jadeite with low brightness (shine), poor grinding and polishing performance, low hardness, as well as poor compact degree, is called bad or tender"Zhong".
Through analyzing the tree structure of jadeite grading evaluation factors, the structure of jadeite is composed of three factors:colour, matrix (base), and craft. The matrix part can be divided into four factors:ground and ground colour, transparency,"Zhong", as well as flaw. Thereby, the relationship between "Zhong"and water-like degree of jadeite, and the relationship between "Zhong"and base of jadeite are clarified.
With the help of the analysis of factors affecting "Zhong", the four elements of structure including mineral particle size, shape, combining ways, and crystalline degree, can be known, In addition, the combination of mineral components within the jadeite affects the old or tender of "Zhong". Therefore, the relationship between "Zhong and the structure ofjadeite is clarified.
The paper shows that the variety of jadeite in pictographic sense and the "Zhong" of jadeite regarded as independent evaluation index are completely different in concept. Finally, the relationship between the "Zhong", varieties, transparency, base, structure, and the problem of old and new "Zhong" of jadeite are all combed in great detail.