It is a cubic crystal with rock-salt structure.
There are several methods for synthesising rubidium fluoride.
One involves reacting rubidium hydroxide with hydrofluoric acid:[1] Another method is to neutralize rubidium carbonate with hydrofluoric acid:[1] Another possible method is to react rubidium hydroxide with ammonium fluoride: The least used method due to expense of rubidium metal is to react it directly with fluorine gas, as rubidium reacts violently with halogens:[1] Rubidium fluoride is a white crystalline substance with a cubic crystal structure that looks very similar to common salt (NaCl).
[2] Rubidium fluoride colors a flame (Bunsen burner flame) purple or magenta red (spectral analysis).
[7] The enthalpy of solution of rubidium fluoride was determined to be −24.28 kJ/mol.