White is the most common color people encounter and also one of the most favorite colors. Whiteness refers to the degree of whiteness of a substance, usually measured by comparing the test sample to a white standard substance under specific wavelength light conditions. Due to the convenience of whiteness detection and its direct and important influence on the performance of transparent minerals and materials, whiteness has become one of the important technical indicators for characterizing the quality of mineral powder functional materials used in polymers, papermaking, coatings, as well as mineral raw materials such as ceramics and glass. For example, the whiteness requirements for electronic ceramics and enamel kaolin are ≥80% and ≥75%, respectively (Dong 2015), while the whiteness requirement for sheet kaolin used in the production of copper-coated paper is ≥90%.