How do you turn black tar into powder?

To turn black tar into powder, you can first allow the tar to dry or cure in a well-ventilated area until it becomes brittle. Once it is sufficiently dried, break it into smaller pieces and then use a mortar and pestle, or a grinder, to pulverize it into a fine powder. Ensure proper safety measures, such as wearing gloves and a mask, as the dust can be harmful to inhale.