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Junitoite
Junitoite is a mineral with formula CaZn2Si2O7·H2O. It was discovered at the Christmas mine in Christmas, Arizona, and described in 1976. The mineral is named for mineral chemist Jun Ito (1926–1978). Description and occurrence Junitoite is transparent to translucent and is colorless, milk-white, or colored due to alteration. Crystals grow up to and have high quality faces. Junitoite occurs in fractures through pods of sphalerite. It formed by retrograde metamorphism and oxidation of tactite, also resulting in kinoite. The mineral is known from New Jersey and the type locality in Arizona. Junitoite occurs in association with apophyllite, calcite, kinoite, smectite, and xonotlite. Crystal structure In 1968, Jun Ito published the results of synthesis of various lead calcium zinc silicates. The formula of one phase, designated ''X3'', was identified as probably CaZnSi2O6·H2O. When he described junitoite, Sidney Williams identified the mineral's formula as CaZn2Si2O7·H2O, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crystal Structure
In crystallography, crystal structure is a description of ordered arrangement of atoms, ions, or molecules in a crystalline material. Ordered structures occur from intrinsic nature of constituent particles to form symmetric patterns that repeat along the principal directions of three-dimensional space in matter. The smallest group of particles in a material that constitutes this repeating pattern is the unit cell of the structure. The unit cell completely reflects the symmetry and structure of the entire crystal, which is built up by repetitive translation of the unit cell along its principal axes. The translation vectors define the nodes of the Bravais lattice. The lengths of principal axes/edges, of the unit cell and angles between them are lattice constants, also called ''lattice parameters'' or ''cell parameters''. The symmetry properties of a crystal are described by the concept of space groups. All possible symmetric arrangements of particles in three-dimensional space ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sorosilicates
Silicate minerals are rock-forming minerals made up of silicate groups. They are the largest and most important class of minerals and make up approximately 90 percent of Earth's crust. In mineralogy, the crystalline forms of silica (silicon dioxide, ) are usually considered to be tectosilicates, and they are classified as such in the Dana system (75.1). However, the Nickel-Strunz system classifies them as oxide minerals (4.DA). Silica is found in nature as the mineral quartz, and its polymorphs. On Earth, a wide variety of silicate minerals occur in an even wider range of combinations as a result of the processes that have been forming and re-working the crust for billions of years. These processes include partial melting, crystallization, fractionation, metamorphism, weathering, and diagenesis. Living organisms also contribute to this geologic cycle. For example, a type of plankton known as diatoms construct their exoskeletons ("frustules") from silica extracted from seawat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrates
In chemistry, a hydrate is a substance that contains water or its constituent elements. The chemical state of the water varies widely between different classes of hydrates, some of which were so labeled before their chemical structure was understood. Chemical nature Inorganic chemistry Hydrates are not inorganic salts "containing water molecules combined in a definite ratio as an integral part of the crystal" that are either bound to a metal center or that have crystallized with the metal complex. Such hydrates are also said to contain ''water of crystallization'' or ''water of hydration''. If the water is heavy water in which the constituent hydrogen is the isotope deuterium, then the term ''deuterate'' may be used in place of ''hydrate''. A colorful example is cobalt(II) chloride, which turns from blue to red upon hydration, and can therefore be used as a water indicator. The notation "''hydrated compound''⋅''n''", where ''n'' is the number of water molecules per formu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zinc Minerals
Zinc is a chemical element; it has Symbol (chemistry), symbol Zn and atomic number 30. It is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 element, group 12 (IIB) of the periodic table. In some respects, zinc is chemically similar to magnesium: both elements exhibit only one normal oxidation state (+2), and the Zn2+ and Mg2+ ions are of similar size. Zinc is the 24th most abundant Abundance of elements in Earth's crust, element in Earth's crust and has five stable isotopes. The most common zinc ore is sphalerite (zinc blende), a zinc sulfide mineral. The largest workable lodes are in Australia, Asia, and the United States. Zinc is refined by froth flotation of the ore, Roasting (metallurgy), roasting, and final extractive metallurgy, extraction using electricity (electrowinning). Zinc is an essential trace element for humans, animals, plants and for microorganisms and is necessary fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcium Minerals
Calcium is a chemical element; it has symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to its heavier homologues strontium and barium. It is the fifth most abundant element in Earth's crust, and the third most abundant metal, after iron and aluminium. The most common calcium compound on Earth is calcium carbonate, found in limestone and the fossils of early sea life; gypsum, anhydrite, fluorite, and apatite are also sources of calcium. The name comes from Latin ''calx'' " lime", which was obtained from heating limestone. Some calcium compounds were known to the ancients, though their chemistry was unknown until the seventeenth century. Pure calcium was isolated in 1808 via electrolysis of its oxide by Humphry Davy, who named the element. Calcium compounds are widely used in many industries: in foods and pharmaceuticals for calci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Natural History Museum, London
The Natural History Museum in London is a museum that exhibits a vast range of specimens from various segments of natural history. It is one of three major museums on Exhibition Road in South Kensington, the others being the Science Museum (London), Science Museum and the Victoria and Albert Museum. The Natural History Museum's main frontage, however, is on Cromwell Road. The museum is home to life and earth science specimens comprising some 80 million items within five main collections: botany, entomology, mineralogy, palaeontology and zoology. The museum is a centre of research specialising in Taxonomy (biology), taxonomy, identification and conservation. Given the age of the institution, many of the collections have great historical as well as scientific value, such as specimens collected by Charles Darwin. The museum is particularly famous for its exhibition of dinosaur skeletons and ornate architecture—sometimes dubbed a ''cathedral of nature''—both exemplified by the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mines ParisTech
Mine, mines, miners or mining may refer to: Extraction or digging *Miner, a person engaged in mining or digging *Mining, extraction of mineral resources from the ground through a mine Grammar *Mine, a first-person English possessive pronoun Military * Mining (military), digging under a fortified military position to penetrate its defenses * Mine warfare ** Anti-tank mine, a land mine made for use against armored vehicles ** Antipersonnel mine, a land mine targeting people walking around, either with explosives or poison gas ** Bangalore mine, colloquial name for the Bangalore torpedo, a man-portable explosive device for clearing a path through wire obstacles and land mines ** Cluster bomb, an aerial bomb which releases many small submunitions, which often act as mines ** Land mine, explosive mines placed under or on the ground ** Naval mine, or sea mine, a mine at sea, either floating or on the sea bed, often dropped via parachute from aircraft, or otherwise lain by surfac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Paris
The University of Paris (), known Metonymy, metonymically as the Sorbonne (), was the leading university in Paris, France, from 1150 to 1970, except for 1793–1806 during the French Revolution. Emerging around 1150 as a corporation associated with the cathedral school of Paris, it was considered the List of medieval universities, second-oldest university in Europe.Charles Homer Haskins: ''The Rise of Universities'', Henry Holt and Company, 1923, p. 292. Officially chartered in 1200 by Philip II of France, King Philip II and recognised in 1215 by Pope Innocent III, it was nicknamed after its theological College of Sorbonne, founded by Robert de Sorbon and chartered by King Louis IX around 1257. Highly reputed internationally for its academic performance in the humanities ever since the Middle Ages – particularly in theology and philosophy – it introduced academic standards and traditions that have endured and spread, such as Doctor (title), doctoral degrees and student nations. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Museum Of Natural History
The National Museum of Natural History (NMNH) is a natural history museum administered by the Smithsonian Institution, located on the National Mall in Washington, D.C., United States. It has free admission and is open 364 days a year. With 4.4 million visitors in 2023, it was the List of most-visited museums in the United States, third most-visited museum in the United States. Opened in 1910, the museum on the National Mall was one of the first Smithsonian buildings constructed exclusively to hold the national collections and research facilities. The main building has an overall area of with of exhibition and public space and houses over 1,000 employees. The museum's collections contain over 146 million specimens of plants, animals, fossils, minerals, rock (geology), rocks, meteorites, human remains, and human cultural artifacts, the largest natural history collection in the world. It is also home to about 185 professional natural history scientists—the largest grou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Harvard University
Harvard University is a Private university, private Ivy League research university in Cambridge, Massachusetts, United States. Founded in 1636 and named for its first benefactor, the History of the Puritans in North America, Puritan clergyman John Harvard (clergyman), John Harvard, it is the oldest institution of higher learning in the United States. Its influence, wealth, and rankings have made it one of the most prestigious universities in the world. Harvard was founded and authorized by the Massachusetts General Court, the governing legislature of Colonial history of the United States, colonial-era Massachusetts Bay Colony. While never formally affiliated with any Religious denomination, denomination, Harvard trained Congregationalism in the United States, Congregational clergy until its curriculum and student body were gradually secularized in the 18th century. By the 19th century, Harvard emerged as the most prominent academic and cultural institution among the Boston B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Arizona
The University of Arizona (Arizona, U of A, UArizona, or UA) is a Public university, public Land-grant university, land-grant research university in Tucson, Arizona, United States. Founded in 1885 by the 13th Arizona Territorial Legislature, it was the first university established in the Arizona Territory. The University of Arizona is one of three universities governed by the Arizona Board of Regents (the University of Arizona, Arizona State University, and Northern Arizona University). , the university enrolled 53,187 students in 22 separate colleges/schools, including the Eller College of Management, the Wyant College of Optical Sciences, the University of Arizona College of Medicine – Phoenix, College of Medicine – Phoenix, the University of Arizona College of Medicine – Tucson, College of Medicine – Tucson, and the James E. Rogers College of Law. The university is Carnegie Classification of Institutions of Higher Education, classified among "R1: Doctoral Universities ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
