Formula: Al3(PO4)2(OH,F)3.5H2O Orthorhombic
Description: Wavellite forms as a groundwater precipitate in aluminous or ferruginous sedimentary rocks, a product of low-grade metamorphism of such rocks or in hydrothermal veins.
JACKSON COUNTY: Wavellite occurs in the Eau Claire Sandstone at several localities between Merillan and Black River Falls. It forms clear, milky white or pale yellow veins, crusts and nodules formed of coalescing botryoidal material made up of concentric shells of radiating acicular crystals. Acicular wavellite also occurs as interstitial cement between the quartz sand grains and as partial replacement of phosphatic brachiopod shell fragments. Some specific spots where wavellite has been found are:
– Roadcut on West Snow Creek Road, north edge of sec. 27 T.22N. R.4W. (Klemic and Mrose, 1972).
– Roadcut on East Snow Creek Road, NE NW SW sec. 23 T.22N. R.4W. (Cordua, 1993 field notes).
– Roadcut on Arnold Road, NE NE SW sec. 11 T.26N. R.4W. (Cordua, 1993 field notes).
– Roadcut on Arnold Road, NW NW SE sec. 2 T.22N. R.4W. (Cordua, 1993 field notes).
– Outcrops in the center of sec. 10 T.22N. R.4W. (Klemic and Mrose, 1972).
Falster (1984) reports crandallite, cacoxenite and variscite in association with the wavellite.