Another Name: magnesium silicofluoride Formulae: MgSiF6•6H2O Molecular Weight: 274.48 UN. NO.:2853 HAZARD CLASS:6.1 H.S. CODE:2826.9000 Physical chemistry properties: white rhombus or acicular crystal, odorless. Its density is 1.788, the melting point is 120¡æ, may lose crystallize water by efflorescence, soluble in water, thin acid, insoluble alcohol thin soluble in silicofluoride. Its water solution appears acidity it can produce fluoride and silicon dioxide with alkali, poisonous. Usage: it can improve the hardness and strength of concrete. It is excellent harden and waterproof matter, and insecticide.