A precise and shared description of gemstones color could greatly help their classification and market evaluation, and the key to develop an efficient color evaluation system for gemstones is the creation of a common descriptive language and assessment method. Nowadays, there is a lack of standards for the determination of color of gemstones, and traditional color assessment is exclusively based on the direct visual observation in some cases with lenses and microscopes. The underlying problem is that light impinging gemstones, due to their physical characteristics, produce scattering and multiple reflecting phenomena. This puts the process of gemstone color assessment out of the scope of classic colorimetry. What needs to be assessed is the overall appearance of the gemstone and this explain why, so far, it is realized mainly by visual inspection. In this study, we investigate the relationship between the use of color measuring instruments and the visual inspection method for the determination of gems color appearance. We set up a perceptual experiment involving 21 participants to correlate the measured and the perceived colors of a set of gemological samples. Results report the correlations between instrumental measures and the visual assessment of gemstones color appearance and can be a potential base for a future standard method for gemstones color assessment.

中文翻译：

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评估宝石的颜色

准确和共享的宝石颜色描述可以极大地帮助其分类和市场评估，开发一种有效的宝石颜色评估系统的关键是创建一种通用的描述性语言和评估方法。如今，缺乏确定宝石颜色的标准，传统的颜色评估完全基于在某些情况下使用透镜和显微镜进行的直接视觉观察。潜在的问题是，撞击光的宝石由于其物理特性而产生散射和多重反射现象。这使宝石颜色评估过程超出了经典比色法的范围。需要评估的是宝石的整体外观，这可以解释为什么到目前为止，它主要是通过视觉检查来实现的。在这项研究中，我们调查了使用颜色测量仪器和视觉检查方法确定宝石颜色外观之间的关系。我们建立了一个涉及21名参与者的感知实验，以关联一组宝石学样品的测量颜色和感知颜色。结果报告了仪器测量值和宝石颜色外观的视觉评估之间的相关性，并且可以为将来的宝石颜色评估标准方法提供潜在的基础。