At my internship, I was asked to use a mortar and pestle. I placed a pigment sample in the mortar, and was asked to apply a downward pushing motion in a circular pattern with my pestle. I kept a firm grip on the pestle and made sure not to use too much force. However, from my days in the kitchen, I was used to "back-and-forth" pattern of moving the pestle, to crush herbs and spices. So this got me thinking, as to whether the grinding pattern (circular vs. back-and-forth) affects the affect the particle size distribution of the final product. I did a bit of digging online, a found a similar question on another forum, which was relatively insufficient to me, as it was specifically about nanosilica.
Therefore, I pose my question, as to whether different solid samples require different grinding patterns, to ensure homogeneity and efficiency in preparing the final sample of desired particle size(roughly)? If so, how is the grinding pattern decided for different samples?
Extension: Or is it so, that the grinding pattern does not play a role(basically negligible), but rather the material of the mortar and pestle and the pressure plays a more significant role in the final particle size?
