Chromatographic Study of Blue-Violet Tanzanite’s Color Appearance

Abstract

Tanzanite is a blue-purple zoisite currently produced only in Tanzania. Tanzanite is loved by the public for its attractive blue-violet color. In this study, the color appearance of tanzanite will be studied chromatically using the CIE 1976 L*a*b* unified color space and the CIECAM16 color appearance model, respectively. The blue color of tanzanite is quantitatively characterized in CIE 1976 L*a*b* uniform color space using an X-Rite SP62 spectrophotometer. The tristimulus values XYZ of tanzanite’s color are input into the CIECAM16 forward model to calculate the color appearance parameters of tanzanite under different light sources, different illumination levels, and different surroundings. And the results show that D65 light source is more suitable for the display of tanzanite. The change in illumination will have a significant effect on Brightness (Q). Darkening of the surroundings will lead to an increase in the lightness of tanzanite. The blue-violet color of tanzanite has a better visual effect when observed in darker conditions.