WGNHS
Wisconsin Geological and Natural History Survey

Northupite

Northupite. From the mineral collection of Brigham Young University Department of Geology, Provo, Utah, Mineral Specimens 807. Courtesy of the U.S. Geological Survey Denver Library Photographic Collection. (Photo by Andrew Silver.)

Formula: Na3Mg(CO3)2Cl Isometric

Description:

A rare carbonate mineral found in dry lake sediments and other unusual sedimentary environments.

DODGE COUNTY: A grain 0.6 cm. long found in the matrix of the Mayville oolitic iron formation was tentatively identified by Hawley and Beaven (1934) as northupite. The mineral was a cube modified by a dodecahedron along one edge, had a saline taste, a refractive index of 1.5145 and effervesced in HCl. The iron formation is exposed in old mines and outcrops in sec. 1, 12 and 13 T.11N. R.16E., east of Neda.