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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] |
Mathematician
A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems. Mathematicians are concerned with numbers, data, quantity, structure, space, models, and change. History One of the earliest known mathematicians were Thales of Miletus (c. 624–c.546 BC); he has been hailed as the first true mathematician and the first known individual to whom a mathematical discovery has been attributed. He is credited with the first use of deductive reasoning applied to geometry, by deriving four corollaries to Thales' Theorem. The number of known mathematicians grew when Pythagoras of Samos (c. 582–c. 507 BC) established the Pythagorean School, whose doctrine it was that mathematics ruled the universe and whose motto was "All is number". It was the Pythagoreans who coined the term "mathematics", and with whom the study of mathematics for its own sake begins. The first woman mathematician recorded by history was Hypati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aneurysm
An aneurysm is an outward bulging, likened to a bubble or balloon, caused by a localized, abnormal, weak spot on a blood vessel wall. Aneurysms may be a result of a hereditary condition or an acquired disease. Aneurysms can also be a nidus (starting point) for clot formation (thrombosis) and embolization. As an aneurysm increases in size, the risk of rupture, which leads to uncontrolled bleeding, increases. Although they may occur in any blood vessel, particularly lethal examples include aneurysms of the Circle of Willis in the brain, aortic aneurysms affecting the thoracic aorta, and abdominal aortic aneurysms. Aneurysms can arise in the heart itself following a heart attack, including both ventricular and atrial septal aneurysms. There are congenital atrial septal aneurysms, a rare heart defect. Etymology The word is from Greek: ἀνεύρυσμα, aneurysma, "dilation", from ἀνευρύνειν, aneurynein, "to dilate". Classification Aneurysms are classified by type, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
19th-century French Mathematicians
The 19th (nineteenth) century began on 1 January 1801 ( MDCCCI), and ended on 31 December 1900 ( MCM). The 19th century was the ninth century of the 2nd millennium. The 19th century was characterized by vast social upheaval. Slavery was abolished in much of Europe and the Americas. The First Industrial Revolution, though it began in the late 18th century, expanding beyond its British homeland for the first time during this century, particularly remaking the economies and societies of the Low Countries, the Rhineland, Northern Italy, and the Northeastern United States. A few decades later, the Second Industrial Revolution led to ever more massive urbanization and much higher levels of productivity, profit, and prosperity, a pattern that continued into the 20th century. The Islamic gunpowder empires fell into decline and European imperialism brought much of South Asia, Southeast Asia, and almost all of Africa under colonial rule. It was also marked by the collapse of the large ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1841 Deaths
Events January–March * January 20 – Charles Elliot of the United Kingdom, and Qishan of the Qing dynasty, agree to the Convention of Chuenpi. * January 26 – Britain occupies Hong Kong. Later in the year, the first census of the island records a population of about 7,500. * January 27 – The active volcano Mount Erebus in Antarctica is discovered, and named by James Clark Ross. * January 28 – Ross discovers the "Victoria Barrier", later known as the Ross Ice Shelf. On the same voyage, he discovers the Ross Sea, Victoria Land and Mount Terror. * January 30 – A fire ruins and destroys two-thirds of the villa (modern-day city) of Mayagüez, Puerto Rico. * February 4 – First known reference to Groundhog Day in North America, in the diary of a James Morris. * February 10 – The Act of Union (''British North America Act'', 1840) is proclaimed in Canada. * February 11 – The two colonies of the Canadas are merged, into the United Province of Canada. * Febru ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1795 Births
Events January–June * January – Central England records its coldest ever month, in the CET records dating back to 1659. * January 14 – The University of North Carolina opens to students at Chapel Hill, becoming the first state university in the United States. * January 16 – War of the First Coalition: Flanders campaign: The French occupy Utrecht, Netherlands. * January 18 – Batavian Revolution in Amsterdam: William V, Prince of Orange, Stadtholder of the Dutch Republic (Republic of the Seven United Netherlands), flees the country. * January 19 – The Batavian Republic is proclaimed in Amsterdam, ending the Dutch Republic (Republic of the Seven United Netherlands). * January 20 – French troops enter Amsterdam. * January 23 – Flanders campaign: Capture of the Dutch fleet at Den Helder: The Dutch fleet, frozen in Zuiderzee, is captured by the French 8th Hussars. * February 7 – The Eleventh Amendment to the United ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
French Mineralogists
French (french: français(e), link=no) may refer to: * Something of, from, or related to France ** French language, which originated in France, and its various dialects and accents ** French people, a nation and ethnic group identified with France ** French cuisine, cooking traditions and practices Fortnite French places Arts and media * The French (band), a British rock band * "French" (episode), a live-action episode of ''The Super Mario Bros. Super Show!'' * ''Française'' (film), 2008 * French Stewart (born 1964), American actor Other uses * French (surname), a surname (including a list of people with the name) * French (tunic), a particular type of military jacket or tunic used in the Russian Empire and Soviet Union * French's, an American brand of mustard condiment * French catheter scale, a unit of measurement of diameter * French Defence, a chess opening * French kiss, a type of kiss involving the tongue See also * France (other) * Franch, a surname * Fren ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lévyne
Levyne or levynite is a zeolite mineral, i.e. a hydrated silicate mineral. There are two forms of levyne: *''Levyne-Na'', the sodium dominated form (), and *''Levyne-Ca'' the calcium dominated form () Levyne crystallizes in the Trigonal - Hexagonal Scalenohedral class. It typically occurs as radiating clusters or fibrous masses that are transparent to translucent in colors ranging from white through reddish and yellowish white to gray. It has a specific gravity of 2.09 - 2.16 and a Mohs hardness of 4.0 to 4.5. It has a vitreous luster and perfect cleavage on 011 Typical occurrence is as an alteration and vesicle filling mineral in basalts. It was named for French mineralogist Armand Lévy (1795–1841). The calcium variety was first described in 1821 for an occurrence in Dalsnipa, Sandoy, Faroe Islands. The sodium variety was described in 1997 for an occurrence in Chojabaru, Nagasaki Prefecture is a prefecture of Japan located on the island of Kyūshū. Nagasaki Prefectu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Willemite
Willemite is a zinc silicate mineral () and a minor ore of zinc. It is highly fluorescent (green) under shortwave ultraviolet light. It occurs in a variety of colors in daylight, in fibrous masses and apple-green gemmy masses. Troostite is a variant in which part of the zinc is partly replaced by manganese, it occurs in solid brown masses. It was discovered in 1829 in the Belgian Vieille-Montagne mine. Armand Lévy was shown samples by a student at the university where he was teaching. Lévy named it after William I of the Netherlands (it is occasionally spelled villemite). The troostite variety is named after Dutch-American mineralogist Gerard Troost. Occurrence Willemite is usually formed as an alteration of previously existing sphalerite ore bodies, and is usually associated with limestone. It is also found in marble and may be the result of a metamorphism of earlier hemimorphite or smithsonite. Crystals have the form of hexagonal prisms terminated by rhombohedral planes: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Roselite
Roselite is a rare arsenate mineral with chemical formula: . It was first described in 1825 for an occurrence in the Rappold mines of Schneeberg, Saxony, Schneeberg, Saxony, Germany and named by Armand Lévy (mineralogist), Armand Lévy after German mineralogist Gustav Rose. It occurs in cobalt bearing hydrothermal environments and was associated with Vein (geology), veins of quartz and chalcedony in the Type locality (geology), type locality. It has also been reported from Italy, Morocco, Chile, British Columbia and several locations in Germany. The pleochroism of roselite depends on chemical composition with darker rose colored varieties being higher in cobalt content and lighter rose colored varieties are higher in calcium and magnesium content (Palache et al., 1960). This gives rise to two different pleochroism schemes, one for dark rose and one for light rose. Dark rose varieties have X: dark rose, Y: pale rose, Z: paler rose. Light rose varieties have X: pale rose, Y: paler ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phillipsite
Phillipsite is a mineral series of the zeolite group; a hydrated potassium, calcium and aluminium silicate, approximating to . The members of the series are phillipsite-K, phillipsite-Na and phillipsite-Ca. The crystals are monoclinic, but only complex cruciform twins are known, these being exactly like twins of harmotome which also forms a series with phillipsite-Ca. Crystals of phillipsite are, however, usually smaller and more transparent and glassy than those of harmotome. Spherical groups with a radially fibrous structure and bristled with crystals on the surface are not uncommon. The Mohs hardness is 4.5, and the specific gravity is 2.2. The species was established by Armand Lévy in 1825 and named after William Phillips. French authors use the name Christianite (after Christian VIII of Denmark), given by A. Des Cloizeaux in 1847. Phillipsite is a mineral of secondary origin, and occurs with other zeolites in the amygdaloidal cavities of mafic volcanic rocks: for example i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Forsterite
Forsterite (Mg2SiO4; commonly abbreviated as Fo; also known as white olivine) is the magnesium-rich end-member of the olivine solid solution series. It is isomorphous with the iron-rich end-member, fayalite. Forsterite crystallizes in the orthorhombic system (space group ''Pbnm'') with cell parameters ''a'' 4.75 Å (0.475 nm), ''b'' 10.20 Å (1.020 nm) and ''c'' 5.98 Å (0.598 nm). Forsterite is associated with igneous and metamorphic rocks and has also been found in meteorites. In 2005 it was also found in cometary dust returned by the Stardust probe. In 2011 it was observed as tiny crystals in the dusty clouds of gas around a forming star. Two polymorphs of forsterite are known: wadsleyite (also orthorhombic) and ringwoodite ( isometric, Cubic crystal system). Both are mainly known from meteorites. Peridot is the gemstone variety of forsterite olivine. Composition Pure forsterite is composed of magnesium, oxygen and silicon. The chemical formula is Mg2SiO4. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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), |
