Development of criteria for determining the color saturation of gemstones
The urgency of the problem is conditioned by spectral methods development providing objectivity and accuracy of gemstones color grading.The purpose of the work: working-out the criteria which allows to determine gemstones saturation based on physics- mathematics patterns and spectral data.Methodology of the research: studying of colored gemstones transmittance spectra, discovery of the regularities and development of physics-mathematics methods for the color saturation grading.Results. The absolute and relative criteria for gemstone saturation grading was suggested as ratio of difference between light transmittance to squared difference between wavelengths at the area of basic chromophore element. Experimental data and allochromatic gemstones saturation calculation examples were presented considering spectral sensitivity of human eye. Gemstones absorption and transmittance spectra research allows to define tone and saturation gemstone color features. To improve tone and saturation definition accuracy, it is necessary to select standard hue of gemstones for wavelengths scale graduating along with spectral sensitivity of human eye.