Influence of Fe2+ on the Color Appearance of Yellow-Green Peridot
Twenty-eight yellow-green color of uniform, high clarity and similar thickness of 5 mm×7 mm oval faceted peridots from Jiaohe Jilin province were examined by LA-ICP-MS and Color i5 to test their chemical compositions and L*, C* and ho. The correlations between Fe2+and color parameters were analyzed, in order to establish the influence on the color appearance of Fe2+. The chemical formula of the twenty-eight peridots is (Mg1.84,Fe0.19)2.04(Si0.982,Al0.001)0.983O4, which was calculated by oxygen atom. It reveals that 0.19 mol Fe2+is concluded in one mol peridot, and Fe2+is the colorant of peridot. Based on the CIE 1976 L*a*b uniform color space, relationships between chromaticity coordinates a*, b* and chromaticity C* were analyzed by Two-way ANOVA, of which the results showing that the influence of b* on C* (rb*×C*=0996) is much more prominent than a* on C* (ra*×c*=-0.383). By partial correlation analysis of the results calculated through CIE LAB color-difference formula, it can be discovered that lightness difference AL* has a better correlation with chromatic aberration AE than AC and AH , whereas the significance level ρ△C*×0.05, ρ△H*×△E*>0.05, it reveals that AE is more sensitive to AL. At the same time, L changes the most with the contributions of Fe2+compared with other parameters of peridot. It is concluded that, with the help of L*, Fe2+has a further influence on the color appearance of peridot.
Tang Weixi Guo Ying Ma Lixia
School of Gemology, China University of Geosciences, Beijing 100083, China
国际会议
长沙
英文
370-373
2011-06-30（万方平台首次上网日期，不代表论文的发表时间）