gems, color science, color theory

A concise introduction to the principles and methods of quantitative color measurement, published by the U.S. National Bureau of Standards. The work explains the scientific foundations of colorimetry, including the relationship between the spectral composition of light, the visual response of the human eye, and the numerical specification of color. Particular attention is given to the Commission Internationale de l’Éclairage (CIE) system, standard observers, tristimulus values, chromaticity coordinates, and the representation of colors on chromaticity diagrams. The publication discusses the measurement and calculation of color from spectral data and the influence of illumination on perceived color. It provides a foundation for the objective description and comparison of colors, with applications in industry, scientific research, and the study of colored materials, including gemstones.