With potassium hydroxide it yields potassium silicofluoride,.
Silicofluoric acid, H2SiF6, is obtained as shown above, and also by the action of sulphuric acid on barium silicofluoride, or by absorbing silicon fluoride in aqueous hydrofluoric acid.
The carbonate, Cs2C03, silicofluoride, Cs2SiF6, borate, Cs20.3B 2 O 3, and the sulphides.
Wood has studied the iridescent colours seen when a precipitate of potassium silicofluoride is produced by adding silicofluoric acid to a solution of potassium chloride, and found that they are due to the same cause, the refractive index of the minute crystals precipitated being about the same as that of the solution, which latter can be varied by dilution.
The crystalline form may be prepared by heating potassium silicofluoride with sodium or aluminium (F.