Potassium Cryolite is a cryolite mixture salt,composed of potassium fluoride and cryolite.It is a white or grey solid with a molar mass of 258.17 g/mol and a density of 2.9 g/cm3.Potassium Cryolite salt is highly stable under normal temperatures and pressures,and has a low toxicity.Its melting point is 1180°C. Potassium Cryolite is a salt composed of potassium fluoride and cryolite. It appears as a white or gray solid with a molar mass of 258.17 g/mol and a density of 2.9 g