Pyrite is the most common sulfide found in many environments. It is a common accessory mineral in igneous, sedimentary and metamorphic rocks. It also is abundant in most hydrothermal deposits. Only the most significant occurrences …
Lafayette County
Pyrolusite
Formula: MnO2 Tetragonal Description: Pyrolusite forms as a weathering product of other manganese minerals, as concretions or dendrites deposited by ground water or as nodules precipitated from lake water. Pyrolusite is often soft and soils the fingers, …
Quartz
Formula: SiO2 Hexagonal Description: Quartz is the most abundant mineral. It is an essential component of granitic igneous rocks, of sedimentary rocks such as sandstone and chert and of metamorphic rocks such as quartzites. It is a …
Safflorite
Formula: (Co,Fe,Ni)As2 Orthorhombic Description: Safflorite is a rare gray metallic mineral forming prismatic to radially fibrous crystals in hydrothermal veins. It is characteristically associated with minerals bearing cobalt, nickel or arsenic such as cobaltite and arsenopyrite. LAFAYETTE …
Sauconite
Formula: Na0.3Zn3(Si,Al)4O10(OH)2.4H2O Monoclinic Description: Sauconite is a zinc-rich clay mineral formed by alteration of sphalerite. It is probably widespread, but under-recognized, in the many mines of the Upper Mississippi Valley zinc-lead district. LAFAYETTE COUNTY: Sauconite is found …
Smithsonite
Description: Massive to botryoidal smithsonite of a form originally called “dry bone ore” by miners. This was a major zinc ore in the mines of southwestern Wisconsin. From the Little Giant Mine, near Shullsburg, Lafayette …
Sphalerite
Formula: ZnS Isometric Description: Banded sphalerite, near Hazel Green in Lafayette County, Wisconsin. Sample is about 1 cm long. Sphalerite occurs in a wide range of hydrothermal environments. It is common with chalcopyrite in exhalative massive …
Strontianite
Formula: SrCO3 Orthorhombic Description: Strontianite forms white acicular to prismatic crystals. It is found as low temperature hydrothermal mineral and a ground water precipitate, primarily in carbonate sedimentary rocks. LAFAYETTE COUNTY: Radiating crystals on limestone were reported from …
Sulfur
Formula: S Orthorhombic Description: Sulfur. From the Bureau of Mines, Mineral Specimens C\01732, courtesy of the U.S. Geological Survey Denver Library Photographic Collection. Sulfur forms around volcanic fumaroles, in sedimentary rocks as a result of bacterial …
Tenorite
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 …