Formula: CuO Monoclinic Description:Tenorite is a black massive mineral found in the oxidized portions of copper deposits where it is associated with other secondary minerals such as cuprite, malachite, azurite, goethite and hematite. It usually forms …
Rusk County
Tetrahedrite-tennantite
Formula: (Cu,Fe,Ag,Zn)12(Sb,As)4S13 Isometric Description:Tetrahedrite forms a solid solution series with tennantite and freibergite in moderate to low temperature hydrothermal deposits.DOUGLAS COUNTY: Irving (1882) reports finding tetrahedrite in “small quantities in traverse veins in copper-bearing rocks”. This occurrence has …
Vivianite
Formula: Fe3(PO4)2.8H2O Monoclinic Description:Vivianite is an iron phosphate mineral found in bladed crystals and clusters of an intense blue to green color. It can form in a variety of environments such as a sedimentary precipitate or …
Wittichenite
Formula: Cu3BiS3 Orthorhombic Description:Wittichenite is an uncommon bismuth-rich mineral found in a variety of hydrothermal deposits.RUSK COUNTY: Small black masses of wittichenite were found in quartz, siderite and copper sulfides at the Flambeau Copper Mine near Ladysmith. …