When I was 12, I made a "smoke bomb" by placing a fire cracker in the bottom of a tube and topping it up with powdered clay. It shoot out a 4 m tall plume of dust, which was cool and all, but I thought it would look a lot more impressive with a black plume.

So I painstakingly ground down some charcoal to fine dust and redid the same experiment. That gave a much more impressive boom, but no dust plume, which puzzled me until I learned about dust explosions.