Formula: (K,Ca,Na)(Fe, Mg,Al)8(Si,Al)12(O,OH)36.nH2O Triclinic Description: Stilpnomelane is a brown micaceous to velvety to fibrous mineral found in various metamorphic rocks, especially those rich in iron. It often occurs with chlorite, epidote, magnetite, hematite and goethite and …
Florence County
Talc
Formula: Mg3Si4O10(OH)2 Triclinic Description: Talc with pen for scale. From the mineral collection of Brigham Young University Department of Geology, Provo, Utah, Mineral Specimens 1073. Courtesy of the U.S. Geological Survey Denver Library Photographic Collection. (Photo by Andrew …
Tantite
Formula: Ta2O5 Triclinic Description: Tantite is a rare mineral found as colorless lustrous grains with other tantalum-bearing minerals in granite pegmatites. FLORENCE COUNTY: Tantite occurs in the contact zone of the Animikie Red Ace complex pegmatite in sec. …
Titanite
Formula: CaTiSiO5 Monoclinic Description:Titanite is a common accessory mineral usually found as tiny grains in many different rocks. It is common in plutonic igneous rocks such as granite, diorite and syenite. Titanite also is a common accessory …
Tourmaline Group
Formula: Na(Al,Fe,Li,Mg,Mn)3(Al,Cr,V,Fe)6(BO3)3Si6O18(O,OH,F)4 Hexagonal Description: Tourmaline var elbaite Animikie Red Ace pegmatite (red) showing comb texture in pegmatite wall zone. With altered Cs-beryl (yellow-green). Near Fern, Florence County, Wisconsin. (Photo by Al Falster.) Tourmaline is a complex group of …
Tremolite
Formula: Ca2Mg5Si8O22(OH)2 Monoclinic Description: Tremolite marble from Florence County, Wisconsin. Field of view 7 cm across. (Photo by Al Falster.) Tremolite is formed by the metamorphism of calcium-rich rocks such as limestone and dolostone. It occurs in numerous …
Triphylite
Formula: LiFePO4 Orthorhombic Description:Triphylite forms bluish-green massive material in complex granitic pegmatites. It is often found with many other rare phosphates. Triphylite readily alters to earthy iron oxides and other iron phosphates.FLORENCE COUNTY: Occurs as nodules up to …
Uraninite
Formula: UO2 Isometric Description: Uraninite with pen for scale. From the mineral collection of Brigham Young University Department of Geology, Provo, Utah, Mineral Specimens 1134. Courtesy of the U.S. Geological Survey Denver Library Photographic Collection. (Photo by Andrew …
Wodginite
Formula: Mn(Sn,Ta)Ta2O8 Monoclinic Description:Wodginite is a rare mineral occurring in complex pegmatites. It forms reddish brown to nearly black tabular to irregular grains.FLORENCE COUNTY: Wodginite is reportedly found in the lithium-rich pegmatites near Fern in T.39N. R.17E. It …