Quality Test Result Hardness Test Result~ 28mm Cube Coconut Shisha Charcoal Visual : Thin; Color : GrayHardness drops:3 drops : 1 cube shattered5 drops : 3 cubes shattered6 drops : 3 cubes shattered7 drops : 1 cube shattered9 drops : 1 cube shattered11 drops : 1 cube shattered(recorded on 17th April 2020) Hardwood Charcoal - Test Result By Forest Product Research & Development Centre