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Clinochrysotile
Chrysotile or white asbestos is the most commonly encountered form of asbestos, accounting for approximately 95% of the asbestos in the United StatesOccupational Safety and Health Administration, U.S. Department of Labor (2007)29 C.F.R. 1910.1001 Appendix J. and a similar proportion in other countries.Institut national de recherche sur la sécurité (1997).Amiante." ''Fiches toxicologiques.'' n° 167. (in French) It is a soft, fibrous silicate mineral in the serpentine subgroup of phyllosilicates; as such, it is distinct from other asbestiform minerals in the amphibole group. Its idealized chemical formula is Mg( Si O)( OH). The material has physical properties which make it desirable for inclusion in building materials, but poses serious health risks when dispersed into air and inhaled. Polytypes Three polytypes of chrysotile are known. These are very difficult to distinguish in hand specimens, and polarized light microscopy must normally be used. Some older publi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chrysolite (other)
Chrysolite may refer to: * Peridot, a gem-quality olivine * Archaically, any of several green or yellow-green-coloured gemstones including ** Topaz, a silicate mineral of aluminium and fluorine ** Chrysoberyl, an aluminate of beryllium ** Zircon, a mineral belonging to the group of nesosilicates ** Tourmaline, a crystalline boron silicate mineral compounded with other elements ** Apatite Apatite is a group of phosphate minerals, usually hydroxyapatite, fluorapatite and chlorapatite, with high concentrations of OH−, F− and Cl− ions, respectively, in the crystal. The formula of the admixture of the three most common e ..., a group of phosphate minerals See also * {{Disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Formula
In chemistry, a chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, such as parentheses, dashes, brackets, commas and ''plus'' (+) and ''minus'' (−) signs. These are limited to a single typographic line of symbols, which may include Subscript and superscript, subscripts and superscripts. A chemical formula is not a chemical nomenclature, chemical name, and it contains no words. Although a chemical formula may imply certain simple chemical structures, it is not the same as a full chemical structural formula. Chemical formulae can fully specify the structure of only the simplest of molecules and chemical substances, and are generally more limited in power than chemical names and structural formulae. The simplest types of chemical formulae are called ''empirical formulae'', which use letters and numbers ind ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Poland
Poland, officially the Republic of Poland, is a country in Central Europe. It is divided into 16 administrative provinces called voivodeships, covering an area of . Poland has a population of over 38 million and is the fifth-most populous member state of the European Union. Warsaw is the nation's capital and largest metropolis. Other major cities include Kraków, Wrocław, Łódź, Poznań, Gdańsk, and Szczecin. Poland has a temperate transitional climate and its territory traverses the Central European Plain, extending from Baltic Sea in the north to Sudeten and Carpathian Mountains in the south. The longest Polish river is the Vistula, and Poland's highest point is Mount Rysy, situated in the Tatra mountain range of the Carpathians. The country is bordered by Lithuania and Russia to the northeast, Belarus and Ukraine to the east, Slovakia and the Czech Republic to the south, and Germany to the west. It also shares maritime boundaries with Denmark and Sweden. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lower Silesia
Lower Silesia ( pl, Dolny Śląsk; cz, Dolní Slezsko; german: Niederschlesien; szl, Dolny Ślōnsk; hsb, Delnja Šleska; dsb, Dolna Šlazyńska; Silesian German: ''Niederschläsing''; la, Silesia Inferior) is the northwestern part of the historical and geographical region of Silesia; Upper Silesia is to the southeast. In the Middle Ages Lower Silesia was part of Piast-ruled Poland. It was one of the leading regions of Poland, and its capital Wrocław was one of the main cities of the Polish Kingdom. Lower Silesia emerged as a distinctive region during the fragmentation of Poland, in 1172, when the Duchies of Opole and Racibórz, considered Upper Silesia since, were formed of the eastern part of the Duchy of Silesia, and the remaining, western part was since considered Lower Silesia. During the Ostsiedlung, German settlers were invited to settle in the sparsely populated region, which until then had a Polish majority. As a result, the region became largely Germanised in th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Złoty Stok
Złoty Stok ( cs, Rychleby, german: Reichenstein, "''Richstone''") is a town in Ząbkowice Śląskie County, Lower Silesian Voivodeship, in south-western Poland. It is situated on the border with the Czech Republic, adjoining the Czech village Bílá Voda. The town is the seat of the administrative district (gmina) called Gmina Złoty Stok, and lies approximately south of Ząbkowice Śląskie and south of the regional capital Wrocław. History The name ''Złoty Stok'' means "golden hillside" in Polish and is a reference to the fact that a gold deposit was mined here in the Middle Ages. Its Czech name is applied to the neighbouring mountain range, the Rychleby Mountains ( cs, Rychlebské hory). The corresponding Polish name is ''Góry Złote'' (Golden Mountains). This range is part of the eastern Sudetes. The area became part of the emerging Polish state in the 10th century under first historic ruler Mieszko I of Poland of the Piast dynasty, and after the fragmentation of Po ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monoclinic
In crystallography, the monoclinic crystal system is one of the seven crystal systems. A crystal system is described by three vectors. In the monoclinic system, the crystal is described by vectors of unequal lengths, as in the orthorhombic system. They form a parallelogram prism. Hence two pairs of vectors are perpendicular (meet at right angles), while the third pair makes an angle other than 90°. Bravais lattices Two monoclinic Bravais lattices exist: the primitive monoclinic and the base-centered monoclinic. For the base-centered monoclinic lattice, the primitive cell has the shape of an oblique rhombic prism;See , row mC, column Primitive, where the cell parameters are given as a1 = a2, α = β it can be constructed because the two-dimensional centered rectangular base layer can also be described with primitive rhombic axes. Note that the length a of the primitive cell below equals \frac \sqrt of the conventional cell above. Crystal classes The table below org ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unit Cell
In geometry, biology, mineralogy and solid state physics, a unit cell is a repeating unit formed by the vectors spanning the points of a lattice. Despite its suggestive name, the unit cell (unlike a unit vector, for example) does not necessarily have unit size, or even a particular size at all. Rather, the primitive cell is the closest analogy to a unit vector, since it has a determined size for a given lattice and is the basic building block from which larger cells are constructed. The concept is used particularly in describing crystal structure in two and three dimensions, though it makes sense in all dimensions. A lattice can be characterized by the geometry of its unit cell, which is a section of the tiling (a parallelogram or parallelepiped) that generates the whole tiling using only translations. There are two special cases of the unit cell: the primitive cell and the conventional cell. The primitive cell is a unit cell corresponding to a single lattice point, it is the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mindat
Mindat may refer to: Places in Burma/Myanmar *Mindat, Chin State, in Burma *Mindat Township, in Burma *Mindat District in Chin State, Burma Other uses *Mindat Min Kanaung Mintha ( my, ကနောင်မင်းသား; 31 January 1820 – 2 August 1866) was crown prince of Burma and son of King Tharrawaddy and younger brother of King Mindon of Burma. Towards the end of the Second Anglo-Burmese Wa ..., a Burmese prince * Mindat.org, an online mineralogy database {{dab, geo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Type Locality (geology)
Type locality, also called type area, is the locality where a particular rock type, stratigraphic unit or mineral species is first identified. If the stratigraphic unit in a locality is layered, it is called a stratotype, whereas the standard of reference for unlayered rocks is the type locality. The term is similar to the term type site in archaeology or the term type specimen in biology. Examples of geological type localities Rocks and minerals * Aragonite: Molina de Aragón, Guadalajara, Spain * Autunite: Autun, France * Benmoreite: Ben More (Mull), Scotland * Blairmorite: Blairmore, Alberta, Canada * Boninite: Bonin Islands, Japan * Comendite: Comende, San Pietro Island, Sardinia * Cummingtonite: Cummington, Massachusetts * Dunite: Dun Mountain, New Zealand. * Essexite: Essex County, Massachusetts, US * Fayalite: Horta, Fayal Island, Azores, Portugal * Harzburgite: Bad Harzburg, Germany * Icelandite: Thingmuli (Þingmúli), Iceland * Ijolite: Iivaara, Kuusamo, Finl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crystal System
In crystallography, a crystal system is a set of point groups (a group of geometric symmetries with at least one fixed point). A lattice system is a set of Bravais lattices. Space groups are classified into crystal systems according to their point groups, and into lattice systems according to their Bravais lattices. Crystal systems that have space groups assigned to a common lattice system are combined into a crystal family. The seven crystal systems are triclinic, monoclinic, orthorhombic, tetragonal, trigonal, hexagonal, and cubic. Informally, two crystals are in the same crystal system if they have similar symmetries (albeit there are many exceptions). Classifications Crystals can be classified in three ways: lattice systems, crystal systems and crystal families. The various classifications are often confused: in particular the trigonal crystal system is often confused with the rhombohedral lattice system, and the term "crystal system" is sometimes used to mean "latti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Mineralogical Association
Founded in 1958, the International Mineralogical Association (IMA) is an international group of 40 national societies. The goal is to promote the science of mineralogy and to standardize the nomenclature of the 5000 plus known mineral species. The IMA is affiliated with the International Union of Geological Sciences (IUGS). The Association supports the activities of Commissions and Working Groups involved on certain aspects of mineralogical practice and facilitates interactions among mineralogists by sponsoring and organising meetings. In particular, the IMA holds its general meeting every four years. The next meeting is scheduled in 2022 in Lyon, France. Presidents The presidents of the IMA have been: * since 2021: Anhuai Lu ** Peking University *2018–2020: Patrick Cordier (born 1961) ** Université de Lille *2016–2018: Peter C. Burns ** University of Notre Dame *2014–2016: Sergey V. Krivovichev (born 1972) ** Saint Petersburg State University *2012–2014: Walter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pecoraite
Pecoraite is a nickel silicate mineral and a member of the serpentine group. It was named after geologist William Thomas Pecora. It is monoclinic and has a chemical composition of Ni3(Si2O5)(OH)4. It is associated with the weathering-and-or oxidation of meteorites or nickel sulfide minerals such as millerite. It is also found in altered ultramafic rocks Ultramafic rocks (also referred to as ultrabasic rocks, although the terms are not wholly equivalent) are igneous and meta-igneous rocks with a very low silica content (less than 45%), generally >18% MgO, high FeO, low potassium, and are compos .... Pecoriate is typically a green, lime green, or bluegreen mineral with a waxy, or earthy luster and a mohs hardness of 2.5. Common textural habits associated with Pecoraite are curved plates, spirals and tubes. It can also be granular and massive. References Nickel minerals Monoclinic minerals Serpentine group {{silicate-mineral-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
