Crushing ore is part of the typical milling process, so depending on the source of your material, it's already milled to a pretty fine dust. I'm way more conce

Crushing ore is part of the typical milling process, so depending on the source of your material, it's already milled to a pretty fine dust. I'm way more concerned with the side effects of the process as others have mentioned. Maybe not heavy metals, but soil PH, and other poisons.