Wagnerite

wagnerite

lazulite

anthophyllite

cordierite

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Formula: Mg2(PO4)F
Anhydrous phosphate containing halogen, wagnerite group
Crystal System: Monoclinic
Specific gravity: 3.15 measured and calculated
Hardness: 5 to 5½
Streak: White
Colour: Yellow, brown, red brown, light grey, green, red, colourless in transmitted light
Solubility: Soluble in acids
Common impurities: Fe,Ca
Environments

Pegmatites
Metamorphic environments

Wagnerite is a rare accessory mineral in metamorphic rocks of moderate to high grade, and is uncommon in pegmatites (Webmin, HOM). It may alter to apatite (Mindat).

Localities

At the Christmas point pegmatite, Khmara Bay, Casey Bay, Napier Complex, Enderby Land, Eastern Antarctica, Antarctica, Wagnerite-Ma5bc, a new polytype, occurs in gneiss as grains to 2 mm across. Textures are consistent with a primary assemblage wagnerite-Ma5bc + plagioclase + apatite + magnetite + ilmenitehematite that crystallised under granulite facies conditions (750 to ~860oC, 6 to 7 kbar). Also present are biotite, quartz, K-feldspar, monazite and xenotime group minerals, corundum, hercynite and sulphides (CM 41.393-411 )
Wagnerite occurs with surinamite, magnesiotaaffeite-6N'3S, garnet, sapphirine, chrysoberyl and cordierite (HOM).

At the type locality, Höllgraben, Pfarrwerfen, St. Johann im Pongau District, Salzburg, Austria, wagnerite has been found in hydrothermal quartz-carbonate veins associated with quartz, ferroan magnesite, lazulite, chlorite, clinochlore and breunnerite (Mindat, Dana, HOM).

At Star Lake, Sherridon District, Manitoba, Canada, wagnerite is a rare mineral found within calcium-depleted, aluminium-rich rocks (CM 30.1161-1165).
The Sherridon Group is dominated by quartz-biotite gneiss. Discontinuous lenses of extremely coarse garnet-cordierite-anthophyllite gneiss occur within the quartz-biotite gneiss units. The garnet-cordierite-anthophyllite rocks are underlain by a sillimanite-bearing unit at Star Lake. Within the garnet-cordierite-anthophyllite rocks, three units are present. From the base upward, these are:
Unit l, characterised by quartz, garnet, anthophyllite and biotite.
Unit 2, characterised by garnet, anthophyllite and minor cordierite.
Unit 3, characterised by anthophyllite and cordierite.
In general, these units are composed of coarse-grained anthophyllite, cordierite and garnet, with biotite-sillimanite and quartz making up much of the remainder of the rock. Dispersed throughout the gneiss are magnetite, hercynite, staurolite and chlorite. The wagnerite, which is less than l% by volume, is found exclusively within Unit 2, closely associated with garnet, cordierite and anthophyllite (CM 30.1161-1165).

At Dolní Bory, Bory, Žďár nad Sázavou District, Vysočina Region, Czech Republic wagnerite occurs as a fine-grained aggregate in a pegmatite (CM 30.1161-1165).
It has been found in a single block of pyrope-rich rock found in a field (CM 30.1161-1165).

At the Silberberg mine, Bodenmais, Regen District, Lower Bavaria, Bavaria, Germany, wagnerite has been found within a piece of magnetite-rich ore (CM 30.1161-1165).

At Ichetuyskoye, Dzhida Basin, Buriatia Republic, Zabaykalsky Krai, Russia, wagnerite occurs in pegmatite and aplite veins of the Kyakhta sillimanite deposit (CM 30.1161-1165).

In the Lepontine area of the Central Alps in Switzerland, wagnerite occurs in a phlogopite schist (CM 30.1161-1165).

At the Dome Rock Mountains, La Paz county, Arizona, USA wagnerite occurs as an accessory phase in a rutile-bearing kyanite quartzite (CM 30.1161-1165).

At the Santa Fe Mountain Beryl Prospect, Clear Creek pegmatite Province, Clear Creek county, Colorado, USA, wagnerite occurs as a trace constituent of rutile-bearing biotite-quartz-plagioclase gneiss (CM 30.1161-1165). The wagnerite is associated with corundum, sillimanite, plagioclase, biotite, monazite-(Ce), apatite, andalusite and tourmaline (HOM).

At the Benson Mines, Benson, Star Lake, St. Lawrence county, New York, USA, wagnerite occurs with isokite in magnetite-hematite deposits associated with sillimanite-garnet-pyroxene rich gneiss (CM 30.1161-1165, Dana).

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