Formula:☐2Al2F6(H2O)
Halide
Crystal System: Isometric
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).
Localities
At Tom's Quarry, Kapunda, Mt Lofty Ranges, South Australia, hydrokenoralstonite has been identified on a
goethite matrix on a single specimen (AJM 17.1.29).
Hydrokenoralstonite from Tom's Quarry -
Image
At the type locality, the Ivigtut Cryolite deposit, Sermersooq, Greenland, Denmark, hydrokenoralstonite is
associated with
thomsenolite and cryolite
(Mindat, AM24.566-576).
Hydrokenoralstonite from the Ivigtut Mine -
Image
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