Xenotime-(Y)

xenotime-(Y)

xenotime-(Yb)

xenotime

chamosite

Images

Formula: Y(PO4)
Phosphate of yttrium, xenotime group, forms a series with xenotime-(Yb) and with chernovite-(Y), zircon is an epitaxial mineral (Mindat)
Crystal System: Tetragonal
Specific gravity: 4.4 to 5.1 measured, 4.277 calculated
Hardness: 4 to 5
Streak: Pale brown, yellowish or reddish, white
Colour: Yellowish brown, reddish brown, light red, flesh-red, light green, grey, greyish white, wine-yellow. Colourless to very light yellowish green, yellow or yellowish brown in transmitted light (Mindat)
Solubility: Very lightly attacked by acids
Environments

Igneous environments
Pegmatites
Metamorphic environments

Localities

At Saint-Pierre-de-Broughton, Quebec, Canada, xenotime-(Y) is an exceedingly rare accessory mineral found in small cavities in albite schist hosting anatase- and brookite- bearing Alpine fissures. It's only associate here is chamosite (R&M 85.6.508-509).

At the Monte Cervandone area, Devero Alp, Baceno, Verbano-Cusio-Ossola Province, Piedmont, Italy, both xenotime and its arsenic analogue chernovite found in the region contain considerable amounts of the rare-earth elements in substitution for yttrium. Because arsenic prevailed hugely over phosphorous in the original hydrothermal solutions, xenotime is much rarer than chernovite, although it occurs fairly commonly on the western side of the Kriegalptal, in gneiss. Yellow to greenish, short-prismatic crystals of xenotime-(Y) are found very sparingly elsewhere; the largest known crystals, to 8 mm, have come from the southern and western slopes of Monte Cervandone, with hematite, rutile, monazite, synchysite and chernovite (MinRec 56.3.320).

At the type locality, Hidra, Flekkefjord, Agder, Norway, xenotime-(Y) occurs in a granite pegmatite (Mindat).
Xenotime-(Y) from Hidra - Image

In the Wassau Complex pegmatites, Marathon county, Wisconsin, USA, xenotime-(Y) has been found in a greisen assemblage associated with cassiterite, ferberite-hübnerite and topaz (R&M 88-4.361-362).

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