Note 10 bis — Chapter XVIII · SILICON AND THE OTHER ELEMENTS OF THE FOURTH GROUP
George Kamensky translation
The sodium salt is far more soluble in water, and crystallises in the hexagonal system. The magnesium salt, MgSiF6, and calcium salt are soluble in water. The salts of hydrofluosilicic acid may be obtained not only by the action of the acid on bases or by double decompositions, but also by the action of hydrofluoric acid on metallic silicates. Sulphuric acid decomposes them, with evolution of hydrofluoric acid and silicon fluoride, and the salts when heated evolve silicon fluoride, leaving a residue of metallic fluoride, R2F2.