Yellow-green coating of metavivianite on green vivianite crystals. Field of view is about 1.0 mm top to bottom. From the Flambeau Mine, Ladysmith, Rusk County, Wisconsin. (Photo and specimen by Dan Behnke.)

Formula: Fe3(PO4)2(OH)2.6H2O Triclinic


Metavivianite is a rare phosphate mineral formed by the alteration of vivianite and other phosphate minerals.

RUSK COUNTY: Forms dark to pale green crystals and coating on vivianite from the oxidized zone, Flambeau Mine, near Ladysmith. (T. Buchholz, pers. comm.)