WGNHS
Wisconsin Geological and Natural History Survey

Cacoxenite

Golden sprays of cacoxenite crystals on matrix. From Mosquito Pit, Indian Mountain, Alabama. Field of view is about 6 mm across. (Image by W. Cordua.)

Formula: AlFe24(PO4)17O6(OH)12.17H2O Hexagonal

Description:

AlFe24(PO4)17O6(OH)12.17H2O Hexagonal

Description: Formed as an alteration of other phosphates. It occurs with minerals such apatite, dufrenite, and wavellite and with iron oxides such as goethite. It is an unusually attractive mineral, often forming small golden fibers and tufts.

CHIPPEWA COUNTY: Tiny acicular crystals are found in goethite concentrations exposed in roadcuts along Route 40, west of Bloomer (WSC, field notes).

JACKSON COUNTY: Tiny acicular crystals of cacoxenite occurs in ferruginous nodules in sandstone of the Eau Claire Formation on East Snow Creek Road, about 4 miles north of Black River Falls (Falster, 1984).