Green Color Appreciation of Gemstones Based on CIE 1976 L*a*b*

Abstract

Based on CIE 1976 L*a*b* uniform color space, L*, a*, b* of jadeite-jade, emerald and turquoise were considered as independent variable, then color green of Jadeite-Jade could be distinguished from other two gemstones with discriminant analysis. Three gemstones discriminant functions were given by the fisher analysis. But in order to reduce false rate 22.9% from turquoise and 7.4% from emerald, green color of three gemstones were reclassified into 6 species by K-Means cluster analysis, and then 6 new discriminant functions were calculated to examine the validity of cluster analysis, finally the linear discriminant function model with high accuracy rate 98.8% were erected from fisher discriminant analysis.