Elpasolite

minerals

pachnolite

chiolite

hydrokenoralstonite

Formula:K2NaAlF6
Halide complex
Specific gravity: 2.995
Hardness: 2½
Streak: White
Colour: Colourless
Environments

Pegmatites

Elpasolite is an uncommon secondary mineral formed in pegmatites.

Localities

At the Cetine mine, Italy, elpasolite occurs on vein quartz in a hydrothermal antimony deposit in silicified limestone, associated with hydrokenoralstonite, rosenbergite, gypsum, fluorite and quartz (HOM).

At the type locality, St Peters Dome, Cheyenne Mining District, El Paso county, Colorado, USA, elpasolite occurs very sparingly with cryolite, pachnolite, thomsenolite, prosopite and gearksutite in vein-like bodies of quartz and microcline in granite. The cryolite was the original deposit and the other minerals were derived by alteration either directly from the cryolite or from other, earlier-formed, secondary fluorides. The elpasolite forms aggregates to 0.5 mm lining solution cavities in massive pachnolite. A little powdery gearksutite is present and formed later than the elpasolite (AM 33.84-87).

In the Morefield pegmatite, Amelia, Virginia, USA, elpasolite occurs in masses with cryolite, chiolite, pachnolite, thomsenolite, prosopite and hydrokenoralstonite (HOM, Dana).

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