Impure powdered cryolite, or "greyolite"
| IUPAC name
| Other names
Sodium aluminium hexafluoride
|Molar mass||209.94 g/mol|
|Melting point||950 °C (1,740 °F; 1,220 K)|
|0.042 g/100 ml (25 °C)|
|Solubility||Insoluble in organic solvents|
|Vapor pressure||~0 mmHg|
Std enthalpy of
|Safety data sheet||Sigma-Aldrich|
|Lethal dose or concentration (LD, LC):|
LD50 (Median dose)
|5,000 mg/kg (rat, oral)|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Sodium hexafluoroaluminate or sodium aluminium hexafluoride is the inorganic compound with the formula Na3AlF6. It occurs naturally as the mineral cryolite, which is also the more common name for this compound.
Cryolite is mostly inert to most reagents and oxidizers.
Sodium hexafluoroaluminate is a white solid, insoluble in water or other solvents.
Sodium hexafluoroaluminate is sold by various chemical suppliers. Can also be bought online.
Natural cryolite can be found in various parts of the world, such as Greenland or several US states.
- 6 NaOH + Al2O3 + 12 HF → 2 Na3AlF6 + 9 H2O
Cryolite precipitates out of the solution, due to its very low solubility in water.
- Source of fluorides
- Make aluminium metal (Hall–Héroult process)
- Mineral collecting
Sodium hexafluoroaluminate has relative low toxicity. It is often used as roach killer.
Cryolite doesn't require special storage conditions. Any clean plastic bottle can be used as storage container.
Cryolite doesn't require special disposal. Can be dumped in the trash.
- Sterten, A.; Maeland, I.; Acta Chemica Scandinavica, Series A: Physical and Inorganic Chemistry; vol. 39; (1985); p. 241 - 258