Study On Color Grading Of Green-Colored Jadeite Jade

Assessment of the color is always an important aspect of quality assurance in allfields of life. In the case of jewelry industry, talking about diamonds and coloredstones, there are already some systematic standards in grading color. While theevaluation of color of jadeite jade, one of the oriental favorite gems, still depends onnaked eyes instead of any color chips or equipment, which means lacking of unifiedand objective criterion. Although there has been GB and some colorimetry methods toquality gem color, handful of research articles are not enough. The results are not asgood as expected and the commercial problems still remain unsolved.This paper aims to produce color chips as an object of reference for evaluationof the green color of jadeite jade in order to define the color grade and solvecommercial problems. This paper determines the distribution position of the greencolor of jadeite in CIE LAB even color space, thus it makes sure accurate color rangecould be get while making color chips, instead of the whole green color range.For the first time we combine the evaluation between business and science, thatis to say, the relationship between Nong, Yang, Zheng and chroma, lightness,hue was researched. That means correct number of color can be translated intolanguage description as we always do in business in order to get the accurate positionand value of the color.The advantage and weakness of color chips, GemDialogue and Munsell, areanalyzed Combined with the distribution of green color of jadeite, the brand newcolor chips for jadeite are planned to come out. By cluster analysis we divided colorchips into6categories to get some rough evaluation of jadeite.Take the distribution of color and polish condition in consideration, we could getthe overall evaluation of green color of jadeite. Though there are some economicproblems, the jadeite market is still heating up, while the evaluation system needs tobe improved to be perfect. This paper supplies a major rule in restraining markettricks and will make the market better and fairer.