Study On The Quality Evaluation Color Chips Of Jadeite-jades’ Green Color By Controlling Color Difference

Based on CIE1976L*a*b*uniform color space,728jadeite-jades’ greencolor were measured by Color i5spectrophotometer. Under A, CWF, D55, D65,D75five different illuminants, color differences of jadeite-jades were analyzed. Itwas concluded that D65was more ideal illuminant for the evaluation ofjadeite-jades’ green color compared with other4illuminants.By applying clustering analysis and discriminant analysis, the resultsshowed that jadeite-jades’ green color were divided well into nine categories byK-Means clustering analysis, and ANOVA showed L*, a*and b*values amongvarious categories were significantly different (all p <0.01). A linear discriminantfunction model of the nine categories of jadeite-jades’ green color wasestablished by Fisher discriminant analysis, which had excellent performance ofdiscriminant with the model checking accuracy of96.85%. Based on L*and C*,jadeite-jades’ green color was divided into nine levels, consisting of fancy vividgreen, fancy intense green, fancy green, fancy deep green, fancy dark green,fancy light green, light green, very light green, faint green. Consideringcommercial value, the best quality is fancy vivid green and the worst is faintgreen. And green quality is getting worse step by step.Three types of jadeite-jades’ green color chips were established. Based onCIE1976L*a*b*color difference formula, ΔE*was15,30or45, while ΔL*was5,10or15, and Δa*, Δb*was10,20or30. The detailed one (521pieces), whichcontained the most color varieties, almost matched all the jadeite-jades’ greencolor. The standard one (66pieces) and the abbreviated one (18pieces) were thesimple, portable ones of the detailed one. The detailed one was improved byanalyzing728jadeite-jades’ green color. And the new type of color chips (126pieces) was divided into the nine levels, which could match basic jadeite-jades’green color.