... Mohs' hardness index of 2.5 - 3.5 and a specific gravity of 2.42. Alumina trihydrate ... ,ATH,surface coated ATH, H-Wf-1st, Aluminium hydroxide, flame retardant,artifical marble,toothpaste abradant,flame ... retardant,Artificial Onyx Filler, etc,Regarding Aluminium Hydroxide for artifical marble,toothpaste abradant,flame retardant ... .03% max.Fe2O3: 0.02% max.Na2O: 0.2% max.L.O.I.: 35% max.Moisture: 0 ...