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Wakefieldite-(Ce)
Wakefieldite-(Ce) () is the cerium analogue of the uncommon rare-earth element vanadate mineral Wakefieldite. It is a member of the xenotime group. Wakefieldite-(Ce) was first described in 1977. It was initially given the name ''kusuïte'' for its type locality in the Kusu deposit, SW of Kinshasa, Zaire Zaire (, ), officially the Republic of Zaire (french: République du Zaïre, link=no, ), was a Congolese state from 1971 to 1997 in Central Africa that was previously and is now again known as the Democratic Republic of the Congo. Zaire was, .... In 1987 it was renamed as the Ce analog of wakefieldite-Y.Handbook of MineralogyWakefieldite-(Ce) References Cerium minerals Vanadate minerals Tetragonal minerals Minerals in space group 141 Minerals described in 1977 {{mineral-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wakefieldite
Wakefieldite () is an uncommon rare-earth element vanadate mineral. There are four main types described of wakefieldite- wakefieldite-(La), wakefieldite-(Ce), wakefieldite-(Nd), and wakefieldite-(Y), depending upon the dominant rare-earth metal ion present. Wakefieldite has a Mohs hardness ranging from 4 to 5. Wakefieldite forms crystals of tetragonal structure. In terms of crystal structure, it is the vanadate analog of the rare-earth phosphate mineral xenotime. Unlike xenotime, it is more favorable for wakefieldite to contain the lighter rare-earth elements over the heavier ones. Due to the lanthanide contraction, the heavier rare earths have smaller ionic radii than the lighter ones. When the phosphate anion is replaced by the larger vanadate anion, the tetragonal crystal system preferentially accommodates the larger light rare-earth elements. Wakefieldite was first described for an occurrence in the Evans Lou mine, St. Pierre de Wakefield, Quebec, Canada Canada ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xenotime Group
The xenotime group is a grouping of minerals containing anhydrous phosphates and vanadates. Xenotime group members Members of the xenotime group include: *Phosphates: **Xenotime ***Xenotime-(Y): ***Xenotime-(Yb): **Pretulite: *Arsenates: **Chernovite (other), Chernovite ***Chernovite-(Y): *Vanadates: **Wakefieldite ***Wakefieldite-(Y): ***Wakefieldite-(La): ***Wakefieldite-(Ce): ***Wakefieldite-(Nd): References Phosphate minerals, # Arsenate minerals, # Vanadate minerals, # {{mineral-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vanadate Minerals
Arsenate minerals usually refer to the naturally occurring orthoarsenates, possessing the (AsO4)3− anion group and, more rarely, other arsenates with anions like AsO3(OH)2− (also written HAsO42−) (example: pharmacolite Ca(AsO3OH).2H2O) or (very rarely) sO2(OH)2sup>− (example: andyrobertsite). Arsenite minerals are much less common. Both the Dana and the Strunz mineral classifications place the arsenates in with the phosphate minerals. Example arsenate minerals include: *Annabergite Ni3(AsO4)2·8H2O *Austinite CaZn(AsO4)(OH) *Clinoclase Cu3(AsO4)(OH)3 *Conichalcite CaCu(AsO4)(OH) *Cornubite Cu5(AsO4)2(OH)4 *Cornwallite Cu2+5(AsO4)2(OH)2 *Erythrite Co3(AsO4)2·8H2O *Mimetite Pb5(AsO4)3Cl *Olivenite Cu2(AsO4)OH Nickel–Strunz Classification -08- Phosphates IMA-CNMNC proposes a new hierarchical scheme (Mills et al., 2009). This list uses it to modify the Classification of Nickel–Strunz ( mindat.org, 10 ed, pending publication). *Abbreviations: **"*" - discredited ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rare-earth Mineral
A rare-earth mineral contains one or more rare-earth elements as major metal constituents. Rare-earth minerals are usually found in association with alkaline to peralkaline igneous complexes, in pegmatites associated with alkaline magmas and in or associated with carbonatite intrusives. Perovskite mineral phases are common hosts to rare-earth elements within the alkaline complexes. Mantle-derived carbonate melts are also carriers of the rare earths. Hydrothermal deposits associated with alkaline magmatism contain a variety of rare-earth minerals. The following includes the relatively common hydrothermal rare-earth minerals and minerals that often contain significant rare-earth substitution: *Aeschynite-( Y or Ce) *allanite *apatite *bastnäsite *britholite * brockite *cerite * Dollaseite-(Ce) *fluocerite *fluorite * gadolinite *monazite *parisite-( Ce or La) *stillwellite *synchysite *titanite *wakefieldite *xenotime *zircon Zircon () is a mineral belonging to the grou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetragonal
In crystallography, the tetragonal crystal system is one of the 7 crystal systems. Tetragonal crystal lattices result from stretching a cubic lattice along one of its lattice vectors, so that the cube becomes a rectangular prism with a square base (''a'' by ''a'') and height (''c'', which is different from ''a''). Bravais lattices There are two tetragonal Bravais lattices: the primitive tetragonal and the body-centered tetragonal. The base-centered tetragonal lattice is equivalent to the primitive tetragonal lattice with a smaller unit cell, while the face-centered tetragonal lattice is equivalent to the body-centered tetragonal lattice with a smaller unit cell. Crystal classes The point groups that fall under this crystal system are listed below, followed by their representations in international notation, Schoenflies notation, orbifold notation, Coxeter notation and mineral examples.Hurlbut, Cornelius S.; Klein, Cornelis, 1985, ''Manual of Mineralogy'', 20th ed., p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cerium
Cerium is a chemical element with the symbol Ce and atomic number 58. Cerium is a soft, ductile, and silvery-white metal that tarnishes when exposed to air. Cerium is the second element in the lanthanide series, and while it often shows the +3 oxidation state characteristic of the series, it also has a stable +4 state that does not oxidize water. It is also considered one of the rare-earth elements. Cerium has no known biological role in humans but is not particularly toxic, except with intense or continued exposure. Despite always occurring in combination with the other rare-earth elements in minerals such as those of the monazite and bastnäsite groups, cerium is easy to extract from its ores, as it can be distinguished among the lanthanides by its unique ability to be oxidized to the +4 state in aqueous solution. It is the most common of the lanthanides, followed by neodymium, lanthanum, and praseodymium. It is the 25th-most abundant element, making up 66 ppm of the Ear ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rare-earth Element
The rare-earth elements (REE), also called the rare-earth metals or (in context) rare-earth oxides or sometimes the lanthanides (yttrium and scandium are usually included as rare earths), are a set of 17 nearly-indistinguishable lustrous silvery-white soft heavy metals. Compounds containing rare earths have diverse applications in electrical and electronic components, lasers, glass, magnetic materials, and industrial processes. Scandium and yttrium are considered rare-earth elements because they tend to occur in the same ore deposits as the lanthanides and exhibit similar chemical properties, but have different electronic and magnetic properties. These metals tarnish slowly in air at room temperature and react slowly with cold water to form hydroxides, liberating hydrogen. They react with steam to form oxides, and at elevated temperature (400°C) ignite spontaneously. These elements and their compounds have no biological function other than in several specialized enzymes, s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vanadate
In chemistry, a vanadate is an anionic coordination complex of vanadium. Often vanadate refers to oxoanions of vanadium, most of which exist in its highest oxidation state of +5. The complexes and are referred to as hexacyanovanadate(III) and nonachlorodivanadate(III), respectively. A simple vanadate ion is the tetrahedral orthovanadate anion, (which is also called vanadate(V)), which is present in e.g. sodium orthovanadate and in solutions of in strong base ( pH > 13). Conventionally this ion is represented with a single double bond, however this is a resonance form as the ion is a regular tetrahedron with four equivalent oxygen atoms. Additionally a range of polyoxovanadate ions exist which include discrete ions and "infinite" polymeric ions. There are also vanadates, such as rhodium vanadate, , which has a statistical rutile structure where the and ions randomly occupy the positions in the rutile lattice, that do not contain a lattice of cations and balancing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kinshasa
Kinshasa (; ; ln, Kinsásá), formerly Léopoldville ( nl, Leopoldstad), is the capital and largest city of the Democratic Republic of the Congo. Once a site of fishing and trading villages situated along the Congo River, Kinshasa is now one of the world's fastest growing megacities. The city of Kinshasa is also one of the DRC's 26 provinces. Because the administrative boundaries of the city-province cover a vast area, over 90 percent of the city-province's land is rural in nature, and the urban area occupies a small but expanding section on the western side. Kinshasa is Africa's third-largest metropolitan area after Cairo and Lagos. It is also the world's largest nominally Francophone urban area, with French being the language of government, education, media, public services and high-end commerce in the city, while Lingala is used as a ''lingua franca'' in the street. Kinshasa hosted the 14th Francophonie Summit in October 2012. Residents of Kinshasa are known as ''Kinoi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zaire
Zaire (, ), officially the Republic of Zaire (french: République du Zaïre, link=no, ), was a Congolese state from 1971 to 1997 in Central Africa that was previously and is now again known as the Democratic Republic of the Congo. Zaire was, by area, the third-largest country in Africa (after Sudan and Algeria), and the 11th-largest country in the world. With a population of over 23 million inhabitants, Zaire was the most-populous officially Francophone country in Africa, as well as one of the most populous in Africa. The country was a one-party totalitarian military dictatorship, run by Mobutu Sese Seko and his ruling Popular Movement of the Revolution party. Zaire was established following Mobutu's seizure of power in a military coup in 1965, following five years of political upheaval following independence from Belgium known as the Congo Crisis. Zaire had a strongly centralist constitution, and foreign assets were nationalized. The period is sometimes referred to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cerium Minerals
Cerium is a chemical element with the Symbol (chemistry), symbol Ce and atomic number 58. Cerium is a hardness, soft, ductile, and silvery-white metal that tarnishes when exposed to air. Cerium is the second element in the lanthanide series, and while it often shows the +3 oxidation state characteristic of the series, it also has a stable +4 state that does not oxidize water. It is also considered one of the rare-earth elements. Cerium has no known biological role in humans but is not particularly toxic, except with intense or continued exposure. Despite always occurring in combination with the other rare-earth elements in minerals such as those of the monazite and bastnäsite groups, cerium is easy to extract from its ores, as it can be distinguished among the lanthanides by its unique ability to be oxidized to the +4 state in aqueous solution. It is the most common of the lanthanides, followed by neodymium, lanthanum, and praseodymium. It is the 25th-most abundance of the chemic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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