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Hausmannite
Hausmannite is a complex oxide, or a mixed oxide, of manganese containing both Divalent, di- and Trivalent, tri-valent manganese. Its chemical formula can be represented as , or more simply noted as , or , as commonly done for magnetite (), the corresponding iron oxide. It belongs to the spinel group and forms tetragonal crystals. Hausmannite is a brown to black metallic mineral with Mohs hardness of 5.5 and a specific gravity of 4.8. The type locality is Oehrenstock (Öhrenstock), Ilmenau, Thuringian Forest, Thuringia, Germany, where it was first described in 1813. Locations include Batesville, Arkansas, US; Ilfeld, Germany; Langban, Sweden; and the Ural Mountains, Russia. High quality samples have been found in South Africa and Namibia where it is associated with other manganese oxides, pyrolusite and psilomelane and the iron-manganese mineral bixbyite. Wilhelm Haidinger (1827) named it in honour of Johann Friedrich Ludwig Hausmann (1782–1859), Professor of Mineralogy, Universi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxide Mineral
The oxide mineral class includes those minerals in which the oxide anion (O2−) is bonded to one or more metal alloys. The hydroxide-bearing minerals are typically included in the oxide class. Minerals with complex anion groups such as the silicates, sulfates, carbonates and phosphates are classed separately. Simple oxides *XO form **Periclase group *** Periclase *** Manganosite **Zincite group *** Zincite *** Bromellite *** Tenorite *** Litharge * form ** Cuprite **Ice * form **Hematite group ***Corundum ***Hematite *** Ilmenite * form **Rutile group ***Rutile *** Pyrolusite *** Cassiterite ** Baddeleyite ** Uraninite ** Thorianite * form **Spinel group ***Spinel ***Gahnite ***Magnetite *** Franklinite ***Chromite ** Chrysoberyl ** Columbite *Hydroxide subgroup: **Brucite ** Manganite ** Romanèchite **Goethite group: *** Diaspore ***Goethite Nickel–Strunz class 4: oxides IMA-CNMNC proposes a new hierarchical scheme (Mills et al., 20 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kalahari Desert
The Kalahari Desert is a large semiarid climate, semiarid sandy savanna in Southern Africa covering including much of Botswana as well as parts of Namibia and South Africa. It is not to be confused with the Angolan, Namibian, and South African Namib coastal desert, whose name is of Khoekhoe language, Khoekhoegowab origin and means "vast place". Etymology ''Kalahari'' is derived from the Tswana language, Tswana word ''Kgala'', meaning "the great thirst", or ''Kgalagadi'', meaning "a waterless place"; the Kalahari has vast areas covered by red sand without any permanent surface water. History The Kalahari Desert was not always a dry desert. The fossil flora and fauna from Gcwihaba, Gcwihaba Cave in Botswana indicates that the region was much wetter and cooler at least from 30 to 11 thousand Before Present, especially after 17,500 BP. Geography Drainage of the desert is by dry black valleys, seasonally inundated pans, and the large salt pan (geology), salt pans of the Mak ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wessels Mine
The Wessels mine is a mine located in the west of South Africa in Northern Cape. Wessels represents one of the largest manganese reserve in South Africa having estimated reserves of 198.8 million tonnes of manganese ore grading 55% manganese metal. See also *Nchwaning mine * Gloria mine *Mamatwan mine The Mamatwan mine is a mining, mine located in the west of South Africa in Northern Cape. Mamatwan represents one of the largest manganese reserves in South Africa having estimated reserves of 433 million tonnes of manganese ore grading 40% mangan ... References Manganese mines Manganese mines in South Africa Economy of the Northern Cape {{SouthAfrica-mine-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Göttingen
The University of Göttingen, officially the Georg August University of Göttingen (, commonly referred to as Georgia Augusta), is a Public university, public research university in the city of Göttingen, Lower Saxony, Germany. Founded in 1734 by George II of Great Britain, George II, King of Great Britain and Electorate of Hanover, Elector of Hanover, it began instruction in 1737 and is recognized as the oldest university in Lower Saxony. Recognized for its historic and traditional significance, the university has affiliations with 47 Nobel Prize winners by its own count. Previously backed by the German Universities Excellence Initiative, the University of Göttingen is a member of the U15 (German Universities), U15 Group of major German research universities, underscoring its strong research profile. It is also a part of prominent international and European academic networks such as Guild of European Research-Intensive Universities, The Guild, the ENLIGHT alliance, and the Hek ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Johann Friedrich Ludwig Hausmann
Johann Friedrich Ludwig Hausmann (22 February 1782 – 26 December 1859) was a German mineralogist. Biography He was born in Hannover and educated in Göttingen, where he obtained a PhD. Two years after making a geological tour of Denmark, Norway and Sweden in 1807, he was placed at the head of a government mining establishment in Westphalia, and established a school of mines at Clausthal in the Harz mountains. In 1811 he was appointed professor of technology and mining, and later of geology and mineralogy at the university of Göttingen, which he occupied until shortly before his death. Additionally, he was secretary of the Royal Academy of Sciences in Göttingen for many years. In 1813, he was elected a foreign member of the Royal Swedish Academy of Sciences. He published observations on the geology and mineralogy of Spain and Italy as well as that of central and northern Europe: he wrote on gypsum, pyrites, felspar, tachylite, cordierite and some eruptive rocks, and devot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wilhelm Haidinger
Wilhelm Karl Haidinger (5 February 179519 March 1871), ennobled as Wilhelm Ritter von Haidinger in 1864, was an Austrian mineralogist. Early life Haidinger's father was the mineralogist Karl Haidinger (1756–1797), who died when Wilhelm was only two years old. The books on mineralogy and the collection of rocks and minerals of his father almost certainly had raised the interest of young Wilhelm. The collection of his uncle, banker Jakob Friedrich van der Nüll, was by far larger and much more precious, even to such a degree that famous professor Friedrich Mohs of Freiberg (Germany) had been asked to describe it in detail. Young Wilhelm Haidinger and the professor often met in the house of Wilhelm's uncle. After completing the ''Normalschule'' and the ''Grammatikalschule'', Wilhelm started out his preacademical training at the local ''Gymnasium''. However, after completing only his first year, the ''Humanitätsclasse'', Wilhelm (now 17 years old) was asked by professor Friedri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bixbyite
Bixbyite is a manganese iron oxide mineral with chemical formula: . The iron/manganese ratio is quite variable and many specimens have almost no iron. It is a metallic dark black with a Mohs hardness of 6.0 – 6.5. It is a somewhat rare mineral sought after by collectors as it typically forms euhedral isometric crystals exhibiting various cubes, octahedra, and dodecahedra. It is commonly associated with beryl, quartz, spessartine, hematite, pseudobrookite, hausmannite, braunite and topaz in pneumatolytic or hydrothermal veins and cavities and in metamorphic rocks. It can also be found in lithophysal cavities in rhyolite. Typical localities are Jhabua and Chhindwara districts, India and the Thomas Range in Juab County, Utah. It is also reported from San Luis Potosi, Mexico; northern Patagonia, Argentina; Girona, Catalonia, Spain; Sweden, Germany, Namibia, Zimbabwe, and South Africa. Bixbyite was named for the American mineralogist Maynard Bixby (1853–1935), responsible ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Psilomelane
Psilomelane is a group name for hard black manganese oxides including hollandite and romanechite. Psilomelane consists of hydrous manganese oxide with variable amounts of barium and potassium. Psilomelane is erroneously, and uncommonly, known as black hematite, despite not being related to true hematite, which is an iron oxide. Formula Generalized formula may be represented as or as . It is sometimes considered to be a hydrous manganese manganate, but of doubtful composition. The amount of manganese present corresponds to 70-80% of Manganese(II) oxide, manganous oxide with 10-15% of available oxygen. Characteristics Psilomelane has no definite chemical composition and occurs as botryoidal and Speleothem, stalactitic masses with a smooth shining surface and submetallic lustre. The mineral is readily distinguished from other hydrous manganese oxides (manganite and Wad (mineral), wad) by its greater Mohs scale of mineral hardness, hardness 5 to 6; the specific gravity varies fro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrolusite
Pyrolusite is a mineral consisting essentially of manganese dioxide ( Mn O2) and is important as an ore of manganese.. It is a black, amorphous appearing mineral, often with a granular, fibrous, or columnar structure, sometimes forming reniform crusts. It has a metallic luster, a black or bluish-black streak, and readily soils the fingers. The specific gravity is about 4.8. Its name is from the Greek for ''fire'' and to ''wash'', in reference to its use as a way to remove tints from glass. Occurrence Pyrolusite and romanechite are among the most common manganese minerals. Pyrolusite occurs associated with manganite, hollandite, hausmannite, braunite, cryptomelane, chalcophanite, goethite, and hematite under oxidizing conditions in hydrothermal deposits. It also occurs in bogs and often results from alteration of manganite. Use The metal is obtained by reduction of the oxide with sodium, magnesium, aluminium, or by electrolysis. Pyrolusite is extensively used for the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Namibia
Namibia, officially the Republic of Namibia, is a country on the west coast of Southern Africa. Its borders include the Atlantic Ocean to the west, Angola and Zambia to the north, Botswana to the east and South Africa to the south; in the northeast, approximating a quadripoint, Zimbabwe lies less than 200 metres (660 feet) away along the Zambezi, Zambezi River near Kazungula, Zambia. Namibia's capital and largest city is Windhoek. Namibia is the driest country in sub-Saharan Africa, and has been inhabited since prehistoric times by the Khoekhoe, Khoi, San people, San, Damara people, Damara and Nama people. Around the 14th century, immigration, immigrating Bantu peoples arrived as part of the Bantu expansion. From 1600 the Ovambo people#History, Ovambo formed kingdoms, such as Ondonga and Oukwanyama. In 1884, the German Empire established rule over most of the territory, forming a colony known as German South West Africa. Between 1904 and 1908, German troops waged a punitive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South Africa
South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. Its Provinces of South Africa, nine provinces are bounded to the south by of coastline that stretches along the Atlantic Ocean, South Atlantic and Indian Ocean; to the north by the neighbouring countries of Namibia, Botswana, and Zimbabwe; to the east and northeast by Mozambique and Eswatini; and it encloses Lesotho. Covering an area of , the country has Demographics of South Africa, a population of over 64 million people. Pretoria is the administrative capital, while Cape Town, as the seat of Parliament of South Africa, Parliament, is the legislative capital, and Bloemfontein is regarded as the judicial capital. The largest, most populous city is Johannesburg, followed by Cape Town and Durban. Cradle of Humankind, Archaeological findings suggest that various hominid species existed in South Africa about 2.5 million years ago, and modern humans inhabited the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
