Formula: Sb3O6(OH) Orthorhombic Description: Stibiconite is a white to yellowish mineral that forms as a result of the alteration of other antimony-rich minerals, such as stibnite. MARATHON COUNTY: Falster( 1987) reports stibiconite as white crusts on sulfosalts …
Marathon County
Stilpnomelane
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 …
Stolzite/Raspite
Formula: Pb(WO)4 Tetragonal/ monoclinic Description: Stolzite and raspite are dimorphs are formed by the oxidation of other tungsten-bearing minerals. MARATHON COUNTY: Stolzite/Raspite has been found as microscopic grains in ferberite/hubnerite in the McGuire Pit, part of the LaDick …
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 …
Tanteuxinite-(Y)
Formula: (Y,Ce,Ca)(Ta,Ti,Nb)2(O,OH)6 Orthorhombic Description:Tanteuxinite-(Y) forms brownish black resinous crystals and masses in granite pegmatites and placer deposits derived from them.MARATHON COUNTY: Tanteuxinite was identified from pegmatites in the Koss pit, a rotten granite quarry several miles west of …
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. …
Tapiolite Series
Formula: (Fe,Mn)(Ta,Nb)2O6 – (Mn,Fe)(Ta, Nb)2O6 Tetragonal Description: Tapiolite-(Fe), Koss Pit, near Wausau, Marathon County, Wisconsin (Photo by Al Falster.) A series exists between ferri-tapiolite and manganotapiolite. These rare minerals are found in complex granite pegmatites. MARATHON COUNTY: A member of …
Thalenite-(Y)
Formula: Y3Si3O10(OH) Monoclinic Description:Thalenite-(Y) is a rare mineral found as pinkish, greenish or brownish grains in complex pegmatites.MARATHON COUNTY: Thalenite-(Y) has been documented as occurring as rare grains in pegmatites in the Koss Pit, a large “rotten …
Thorite
Formula: (Th,U)SiO4 Tetragonal Description:Thorite is a rare mineral found in pegmatites and hydrothermal deposits.MARATHON COUNTY: Thorite is found in the pegmatites associated with the amphibole syenites of the Stettin pluton. Some grains and clusters may be several centimeters …
Thorogummite
Formula: (Th,U)(SiO4)1-x(OH)4x Tetragonal Description:Thorogummite is formed by the alteration of other thorium-rich minerals, such as thorite. IMA currently lists its status as a species as “doubtful.”MARATHON COUNTY: Much of the thorite found in the pegmatites of the Stettin …