WGNHS
Wisconsin Geological and Natural History Survey

Erythrite

Erythrite. From the mineral collection of Brigham Young University Department of Geology, Provo, Utah, Mineral Specimens 496. Courtesy of the U.S. Geological Survey Denver Library Photographic Collection. (Photo by Andrew Silver.)

Formula: Co3(AsO4)2.8H20 Monoclinic

Description:

Erythrite is a pink to purple powdery to acicular mineral formed as a result of near-surface alteration of other cobalt-rich minerals.

LAFAYETTE COUNTY: Erythrite was tentatively reported as intermixed with melanterite as an alteration of an unidentified cobalt mineral intergrown with marcasite at the Martin Mine south of Benton (SW SE Sec. 16 T.1N. R.1E.) (Heyl, et al., 1959).

MARATHON COUNTY: Erythrite was tentatively identified on iron-oxide stained surfaces on rock piles in the NE SW sec. 24 T.29N. R.7E. in Wausau. (LaBerge and Myers, 1983).