Development of quality control materials (QCMs) for ruby color grading

Develop a series of quality control materials (QCMs) for ruby color grading. Ruby was synthesized using flame melting method, and the ruby samples were cut and polished to prepare samples of the same size and glossiness. According to GB/T 32863-2016, D50 standard light source is used, and 9 experienced jewelry grading technicians collaborate to determine the standard value and uncertainty. The determined values mainly include color tone, brightness, and saturation, with Munsell hue ranging from 2.78RP to 1.25R, Munsell value ranging from 3.4 to 6.7, and Munsell chroma ranging from 7.4 to 11.0. This series of substances provides technical support for quality control of ruby products, confirmation of experimental methods, and personnel identification and evaluation.