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Brookite
Brookite is the orthorhombic variant of titanium dioxide (TiO2), which occurs in four known natural polymorphic forms (minerals with the same composition but different structure). The other three of these forms are akaogiite (monoclinic), anatase (tetragonal) and rutile (tetragonal). Brookite is rare compared to anatase and rutile and, like these forms, it exhibits photocatalytic activity. Brookite also has a larger cell volume than either anatase or rutile, with 8 TiO2 groups per unit cell, compared with 4 for anatase and 2 for rutile.Anatase and Brookite . Wikis.lib.ncsu.edu (2007-05-08). Retrieved on 2011-10-14. (Fe), |
Brookite
Brookite is the orthorhombic variant of titanium dioxide (TiO2), which occurs in four known natural polymorphic forms (minerals with the same composition but different structure). The other three of these forms are akaogiite (monoclinic), anatase (tetragonal) and rutile (tetragonal). Brookite is rare compared to anatase and rutile and, like these forms, it exhibits photocatalytic activity. Brookite also has a larger cell volume than either anatase or rutile, with 8 TiO2 groups per unit cell, compared with 4 for anatase and 2 for rutile.Anatase and Brookite . Wikis.lib.ncsu.edu (2007-05-08). Retrieved on 2011-10-14. (Fe), |
Titanium Dioxide
Titanium dioxide, also known as titanium(IV) oxide or titania , is the inorganic compound with the chemical formula . When used as a pigment, it is called titanium white, Pigment White 6 (PW6), or CI 77891. It is a white solid that is insoluble to water, although mineral forms can appear black. As a pigment, it has a wide range of applications, including paint, sunscreen, and food coloring. When used as a food coloring, it has E number E171. World production in 2014 exceeded 9 million tonnes. It has been estimated that titanium dioxide is used in two-thirds of all pigments, and pigments based on the oxide have been valued at a price of $13.2 billion. Structure In all three of its main dioxides, titanium exhibits octahedral geometry, being bonded to six oxide anions. The oxides in turn are bonded to three Ti centers. The overall crystal structure of rutile is tetragonal in symmetry whereas anatase and brookite are orthorhombic. The oxygen substructures are all slight distort ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Titanium
Titanium is a chemical element with the symbol Ti and atomic number 22. Found in nature only as an oxide, it can be reduced to produce a lustrous transition metal with a silver color, low density, and high strength, resistant to corrosion in sea water, aqua regia, and chlorine. Titanium was discovered in Cornwall, Great Britain, by William Gregor in 1791 and was named by Martin Heinrich Klaproth after the Titans of Greek mythology. The element occurs within a number of minerals, principally rutile and ilmenite, which are widely distributed in the Earth's crust and lithosphere; it is found in almost all living things, as well as bodies of water, rocks, and soils. The metal is extracted from its principal mineral ores by the Kroll and Hunter processes. The most common compound, titanium dioxide, is a popular photocatalyst and is used in the manufacture of white pigments. Other compounds include titanium tetrachloride (TiCl4), a component of smoke screens and catalysts; and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rutile
Rutile is an oxide mineral composed of titanium dioxide (TiO2), the most common natural form of TiO2. Rarer Polymorphism (materials science), polymorphs of TiO2 are known, including anatase, akaogiite, and brookite. Rutile has one of the highest refractive index, refractive indices at visible wavelengths of any known crystal and also exhibits a particularly large birefringence and high dispersion (optics), dispersion. Owing to these properties, it is useful for the manufacture of certain optical elements, especially Polarization (waves), polarization optics, for longer light, visible and infrared, infrared wavelengths up to about 4.5 micrometres. Natural rutile may contain up to 10% iron and significant amounts of niobium and tantalum. Rutile derives its name from the Latin ('red'), in reference to the deep red color observed in some specimens when viewed by transmitted light. Rutile was first described in 1803 by Abraham Gottlob Werner. Occurrence Rutile is a common accessory ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anatase
Anatase is a metastable mineral form of titanium dioxide (TiO2) with a tetragonal crystal structure. Although colorless or white when pure, anatase in nature is usually a black solid due to impurities. Three other polymorphs (or mineral forms) of titanium dioxide are known to occur naturally: brookite, akaogiite, and rutile, with rutile being the most common and most stable of the bunch. Anatase is formed at relatively low temperatures and found in minor concentrations in igneous and metamorphic rocks. Thin films of TiO2-coated glass show antifogging and self-cleaning properties under ultraviolet radiation. Anatase is always found as small, isolated, and sharply developed crystals, and like rutile, it crystallizes in a tetragonal system. Anatase is metastable at all temperatures and pressures, with rutile being the equilibrium polymorph. Nevertheless, anatase is often the first titanium dioxide phase to form in many processes due to its lower surface energy, with a transforma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aldan Shield
Aldan Shield (russian: Алданский щит) is a shield in Siberia. It is an exposed basement of the Siberian Craton. Together with the Anabar Shield further to the northwest, the Aldan Shield is one of the main features of the craton. The Aldan Shield geological region coincides geographically with parts of the Aldan Highlands and Olyokma-Chara Plateau, located at the southern end of the Sakha Republic and the eastern end of Irkutsk Oblast.Google Earth The exposed crust parts of the shield date back to the Archean and reflect the first phases of accretion of the crust. They only emerge in a few areas, the eastern and northern sectors of the shield being largely covered by sediments accumulated between the end of the Precambrian and the Cambrian, while in the western and southern regions they have undergone processes of tectonic rejuvenation that have brought about the formation of new structures above and below. On the Aldan Shield there is the only charoite deposit know ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Armand Lévy (mineralogist)
Serve-Dieu Abailard "Armand" Lévy (14 November 1795 – 29 July 1841) was a French mathematician and mineralogist. He is remembered in the Haüy-Lévy notation for describing mineral crystal structures. Life Lévy was born in Paris where his Jewish businessman father had married Céline Mailfert, a Catholic. Although his birth and death records have his given names as Serve-Dieu Abailard, he registered with the Geological Society of London under the name Armand. Armand Lévy studied mathematics, passing his agrégation in 1816 from the École Normale Supérieure. His Jewish origin prevented him from obtaining jobs in France and took up an offer Collège Royal on Reunion Island. While sailing to the Indian Ocean, his ship was wrecked off Plymouth. He then settled in London where he made a living by giving mathematics tuitions and in 1820 he met a mineral dealer, Henry Heuland, who asked him to categorise his collection as part of its sale to Charles Hampden Turner. In London h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxide Minerals
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. The minerals with complex anion groups such as the silicates, sulfates, carbonates and phosphates are classed separately. Simple oxides: *XO **Periclase group ***Periclase ***Manganosite **Zincite group ***Zincite *** Bromellite ***Tenorite ***Litharge * **Cuprite **Ice * **Hematite group ***Corundum ***Hematite ***Ilmenite * **Rutile group ***Rutile ***Pyrolusite *** Cassiterite ** Baddeleyite **Uraninite **Thorianite * **Spinel group ***Spinel ***Gahnite ***Magnetite ***Franklinite *** Chromite **Chrysoberyl **Columbite *Hydroxide subgroup: **Brucite **Manganite ** Romanèchite **Goethite group: ***Diaspore ***Goethite Nickel–Strunz Classification -04- Oxides IMA-CNMNC proposes a new hierarchical scheme (Mills et al., 2009). This list uses it to mod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Akaogiite
Akaogiite ( IMA symbol Aka) is an exceedingly rare mineral, one of the natural forms of titanium dioxide (TiO2). It is a high-pressure polymorph of TiO2, along with anatase, brookite and another high-pressure phase called "TiO2 II". Rutile is the stable polymorph of TiO2, most commonly found at standard temperatures and pressures. Akaogiite can be found at the Nördlinger Ries Crater, a meteor crater Meteor Crater, or Barringer Crater, is a meteorite impact crater about east of Flagstaff and west of Winslow in the desert of northern Arizona, United States. The site had several earlier names, and fragments of the meteorite are official ... in Germany, where the extreme pressure during the impact allowed its formation. References Oxide minerals Titanium minerals Monoclinic minerals {{oxide-mineral-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnet Cove, Arkansas
Magnet Cove is a census-designated place (CDP) and former town in Hot Spring County, Arkansas, United States. It is located in the Ouachita Mountains southeast of Hot Springs, on Arkansas Highway 51 north of U.S. Highway 270. As of the 2020 census, the town of Magnet Cove had a population of 692. Geography The boundaries of the former town, with a population of 5, represented only a very small portion of the overall Magnet Cove community. (Note: The purple rectangle in the lower center of the map is the entire incorporated town.) The community suspended its incorporation in 2006. As of 2015, the U.S. Census Bureau recognized an area along Highway 51 extending from Harver Hills Road in the southeast to Gourdneck Valley Road in the northwest as the Magnet Cove Census Designated Place. The CDP occupies the topographic Magnet Cove, a broad valley along Stone Quarry Creek surrounded by hills, and includes the Magnet Cove High School and Elementary School, as well as Magnet Cove United ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Olyokma-Chara Plateau
The Olyokma-Chara Plateau ( rus, Олёкмо-Чарское плоскогорье; sah, Өлүөхүмэ-Чаара хаптал хайалаах сир) is a mountainous area in the Sakha Republic and Irkutsk Oblast, Far Eastern Federal District, Russia.Google Earth A small section is in Kalarsky District, northernmost Zabaykalsky Krai. Charoite, a rare mineral, is found in the Murun Massif area of the plateau, rising between rivers Chara and Tokko. Geography The Olyokma-Chara Plateau is located to the south of the Lena, at the southwestern end of the Sakha Republic in Olyokminsky District, and the eastern end of Irkutsk Oblast, Bodaybinsky District. The plateau is bound by the Chara River, a left tributary of the Olyokma river to the west and the Olyokma, a left tributary of the Lena, to the east. The Tokko River, the largest tributary of the Chara, crosses the uplands from south to north. To the south rises the Udokan Range of the Stanovoy Highlands and to the north ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Siberia
Siberia ( ; rus, Сибирь, r=Sibir', p=sʲɪˈbʲirʲ, a=Ru-Сибирь.ogg) is an extensive geographical region, constituting all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has been a part of Russia since the latter half of the 16th century, after the Russians conquered lands east of the Ural Mountains. Siberia is vast and sparsely populated, covering an area of over , but home to merely one-fifth of Russia's population. Novosibirsk, Krasnoyarsk and Omsk are the largest cities in the region. Because Siberia is a geographic and historic region and not a political entity, there is no single precise definition of its territorial borders. Traditionally, Siberia extends eastwards from the Ural Mountains to the Pacific Ocean, and includes most of the drainage basin of the Arctic Ocean. The river Yenisey divides Siberia into two parts, Western and Eastern. Siberia stretches southwards from the Arctic Ocean to the hills of north-ce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
