HSL Chromaticity Characteristic of Green Jadeite Jade

The colour of jadeite jade is one of the important linkages for evaluation of quality and value of jadeite jade. In recent years, scholars have carried out many studies on the evaluation of jadeite jade colour and have made certain achievements. However, these achievements have obviously not been applied or promoted in the market, because these evaluations are based on instrument indexes. This research is based on the principle of colorimetry, using the HSL colour space model as the theoretical basis. Under the 5 500 K white light source, the authors collected photos of green jadeite jade samples by colour digital camera, and analyzed the HSL value of each sample. The authors quantified the green jadeite colour parameters in HSL value and got the HSL distribution. Based on these analysis, the authors obtained the threshold of HSL value of 9 kinds of green jadeite jades:melon green, emerald green, bright green, yellow green, bean green, light bean green, light green, pale green and grey green, and the chromaticity characteristics of these green jadeite jade are determined. The authors expect to find out a simple, convenient and scientific method for the evaluation and grading of colour of green jadeite jade.