WGNHS
Wisconsin Geological and Natural History Survey

Tanteuxinite-(Y)

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Tanteuxinite-(Y) crystal, coated with yellow secondary alteration minerals, from a small cavity in granite. Wimmer #3 pit, Marathon County. Field of view is 0.8 mm left to right. (Dan Behnke image.)

Formula: (Y,Ce,Ca)(Ta,Ti,Nb)2(O,OH)6 Orthorhombic

Description:Tanteuxinite-(Y) forms brownish black resinous crystals and masses in granite pegmatites and placer deposits derived from them.MARATHON COUNTY: Tanteuxinite was identified from pegmatites in the Koss pit, a rotten granite quarry several miles west of Wausau (Tom Buchholz, pers. com.)Tiny grains of a mineral tentatively identified as a “tanteuxinite-like” mineral was reported from pegmatites at the Wimmer #3 pit, south of Rib Mountain, near Wausau. (Tom Buchholz, pers. com.).