Hydrokenoralstonite

halide

Formula:☐2Al2F6(H2O)
Halide
Specific gravity: 2.50 to 2.68
Hardness: 4½
Streak: White
Colour: Colourless to white
Solubility: Decomposed by sulphuric acid with evolution of HF Dana
Environments

Pegmatites
Metamorphic environments
Hydrothermal environments

Hydrokenoralstonite is an alteration product of cryolite (Webmin). It occurs in some granite pegmatites and greisenized zones rich in fluorine, and also in a hydrothermal antimony deposit in silicified limestone. Associated minerals include thomsenolite, cryolite, pachnolite, chiolite, elpasolite, colquiriite, gearksutite, weberite, prosopite and fluorite (HOM).

At Tom's Quarry, Kapunda, Mt Lofty Ranges, South Australia, hydrkenoralstonite has been identified on a goethite matrix on a single specimen (AJM 17.1.29).

At the type locality, the Ivigtut Cryolite deposit, Sermersooq, Greenland, Denmark, hydrokenoralstonite is associated with thomsenolite and cryolite (Mindat, AM24.566-576).

Back to Minerals