MgSiF6.6H2O 98% Min, MgSO4.7H2O 0.5% Max, H2SiF60.5%Max, H2O 0.5% Max Insolublle Water 0.2% Max Purity: 98.5%Appearance: acicular crystal.Odourless.The relative density is 1.788.The melting point is 120°C(decomposition).Hard to deliquesce.But the crystal water will be lost under efflorescence.It is decomposed by dehydration when the temperature is over 80°C,and at the same time gives out silicon ...