Formula: (Cu,Al)2H2Si2O5(OH)4.nH2O Monoclinic
Description: Chrysocolla is a blue copper-rich clay mineral that forms as an alteration product of other copper minerals in supergene and oxidized zones.
IOWA COUNTY: Reported at the Steppler Farm, 4 miles SW of Highland in the SE NE Sec. 7 T.6N R.1E. Here it is associated with malachite, azurite, chalcocite, chalcopyrite, aurichalcite, sphalerite and smithsonite (W.G.N.H.S. files). – Reported as a coating in the copper deposits near Mineral Point (Irving, 1883).
RUSK COUNTY: Chrysocolla and related cupriferous clays occurred in the oxidized zone at the Flambeau Mine, near Ladysmith. The chrysocolla formed blue, green, yellow and ocherous masses and coatings on other copper minerals.