<p>The process of blending grinding layer mixtures constitutes a fundamental step in the manufacturing of superabrasive grinding tools, ranking among the initial and most consequential procedures. Superabrasives are composed of diamond and cubic boron nitride grains. To achieve optimal performance during the grinding process, the superabrasives must be mixed homogeneously. At this juncture, the influence of mixing parameters such as speed and time on the quality of the mixture remains to be elucidated. Furthermore, there is an absence of a method for evaluating the mixing quality of diamond grits in vitrified bonding mixtures. A grinding layer mixture is distinguished by a dispersed distribution of particle sizes, with an unknown quantity of particles. In this study, the utilization of established mixing indices from the extant literature has been examined for their efficacy in describing the mixing quality of grinding layer mixtures. In addition, a novel variance-based mixing index is hereby put forward. The novel mixing index uses the Voronoi regions to calculate the variation coefficient based on the areas of those regions. Additionally, a simulation is employed to elucidate the discrepancy between the Voronoi-based and grid-based variation coefficients. The findings indicate that the Voronoi-based approach exhibits enhanced sensitivity in detecting clusters and is less susceptible to variations in their number. A series of investigations were conducted using the Voronoi-based method to ascertain the influence of the mixing time and speed on the quality of different grinding tool mixtures. It was determined that the diamond grains in the mixture attained a statistically mixed state within the initial minute of the mixing process. The mixing speed does not exert a significant influence on the quality of the mixture.</p>