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Formula: MnAl2(PO4)2(F,OH)2.5.5H2O
Hydrated phosphate
Crystal System: Triclinic
Specific gravity: 2.35 measured, 2.46 calculated
Streak: White
Colour: White to off-white
Environments
Nordgauite is a late stage secondary hydrothermal mineral
in altered zwieselite-triplite
masses in a zoned granite
pegmatite. Associated minerals include
fluorapatite, sphalerite,
uraninite,
columbite-tantalite,
phosphosiderite and
whiteite-jahnsite (inclusions)
(HOM).
Localities
At the type locality, the Hagendorf South Pegmatite, Hagendorf, Waidhaus, Neustadt an der Waldnaab District, Upper
Palatinate, Bavaria, Germany, nordgauite and kayrobertsonite were
found in association with fluorapatite in cavities in altered
zwieselite-triplite at a depth of
60 to 67 m in the mine. Nordgauite occurs as millimetre-sized compact white rounded waxy nodules with fibrous rims
(AJM 19.1.8-9). Nordgauite has formed as a late-stage hydrothermal phase in the
secondary phosphate suite, the end-product of the decomposition
of zwieselite-triplite. Associated
minerals include fluorapatite,
sphalerite,
uraninite,
columbite-tantalite,
phosphosiderite, whiteite and
jahnsite
(Mindat).
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