Formula: (Zn,Cu)5(CO3)2(OH)6 Monoclinic
Description: Aurichalcite forms bluish green radical fibrous crystals in zones where zinc and copper minerals are subjected to oxidization and redeposition of the metals in the present of carbon dioxide.
IOWA COUNTY: Reportedly found as “pale blue silky tuffs” at the Eberle mine, 5 miles north of Cobb in the NW 1/4 NW 1/4 Sec. 2 T.^N. R.1E. It is here associated with malachite, azurite, cuprite, chalcocite, sphalerite and smithsonite (Heyl, et. al., 1959; Wisc. Geol. and Nat. Hist. Surv. files).
— Found at the Steppler Farm, 4 miles southwest of Highland on County Trunk I in the SE 1/4 SE 1/4 Sec. 7 T.6N. R.1E. Associated minerals are chalcopyrite, chalcocite, azurite, malachite, chrysocolla, sphalerite and smithsonite (WGNHS files) (Heyl et al., 1959).
LAFAYETTE COUNTY: Found as tiny bluish green radiating crystals associated with calcite, chalcopyrite and sphalerite on old mine dumps on the SE edge of the SE 1/4 Sec. 12 T.1N. R.2E (Heyl et al., 1959).