|
Troilite
Troilite is a rare iron sulfide mineral with the simple formula of FeS. It is the iron-rich endmember of the pyrrhotite group. Pyrrhotite has the formula Fe(1-x)S (x = 0 to 0.2) which is iron deficient. As troilite lacks the iron deficiency which gives pyrrhotite its characteristic magnetism, troilite is non-magnetic. Troilite can be found as a native mineral on Earth but is more abundant in meteorites, in particular, those originating from the Moon and Mars. It is among the minerals found in samples of the meteorite that struck Russia in Chelyabinsk on February 15th, 2013. Uniform presence of troilite on the Moon and possibly on Mars has been confirmed by the Apollo, Viking and Phobos space probes. The relative intensities of isotopes of sulfur are rather constant in meteorites as compared to the Earth minerals, and therefore troilite from Canyon Diablo meteorite is chosen as the international sulfur isotope ratio standard, the Canyon Diablo Troilite (CDT). Structure Troilit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reference Materials For Stable Isotope Analysis
Isotopic reference materials are compounds (solids, liquids, gasses) with well-defined isotopic compositions and are the ultimate sources of accuracy in mass spectrometric measurements of isotope ratios. Isotopic references are used because mass spectrometers are highly fractionating. As a result, the isotopic ratio that the instrument measures can be very different from that in the sample's measurement. Moreover, the degree of instrument fractionation changes during measurement, often on a timescale shorter than the measurement's duration, and can depend on the characteristics of the sample itself. By measuring a material of known isotopic composition, fractionation within the mass spectrometer can be removed during post-measurement data processing. Without isotope references, measurements by mass spectrometry would be much less accurate and could not be used in comparisons across different analytical facilities. Due to their critical role in measuring isotope ratios, and in pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfide Mineral
The sulfide minerals are a class of minerals containing sulfide (S2−) or disulfide (S22−) as the major anion. Some sulfide minerals are economically important as metal ores. The sulfide class also includes the selenides, the tellurides, the arsenides, the antimonides, the bismuthinides, the sulfarsenides and the sulfosalts.http://www.minerals.net/mineral/sort-met.hod/group/sulfgrp.htm Minerals.net Dana Classification, SulfidesKlein, Cornelis and Cornelius S. Hurlbut, Jr., 1986, ''Manual of Mineralogy'', Wiley, 20th ed., pp 269-293 Sulfide minerals are inorganic compounds. Minerals Common or important examples include: * Acanthite *Chalcocite *Bornite * Galena * Sphalerite *Chalcopyrite *Pyrrhotite *Millerite *Pentlandite *Covellite *Cinnabar *Realgar *Orpiment *Stibnite *Pyrite *Marcasite *Molybdenite Sulfarsenides: *Cobaltite *Arsenopyrite *Gersdorffite Sulfosalts: *Pyrargyrite *Proustite *Tetrahedrite *Tennantite *Enargite *Bournonite * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfide Mineral
The sulfide minerals are a class of minerals containing sulfide (S2−) or disulfide (S22−) as the major anion. Some sulfide minerals are economically important as metal ores. The sulfide class also includes the selenides, the tellurides, the arsenides, the antimonides, the bismuthinides, the sulfarsenides and the sulfosalts.http://www.minerals.net/mineral/sort-met.hod/group/sulfgrp.htm Minerals.net Dana Classification, SulfidesKlein, Cornelis and Cornelius S. Hurlbut, Jr., 1986, ''Manual of Mineralogy'', Wiley, 20th ed., pp 269-293 Sulfide minerals are inorganic compounds. Minerals Common or important examples include: * Acanthite *Chalcocite *Bornite * Galena * Sphalerite *Chalcopyrite *Pyrrhotite *Millerite *Pentlandite *Covellite *Cinnabar *Realgar *Orpiment *Stibnite *Pyrite *Marcasite *Molybdenite Sulfarsenides: *Cobaltite *Arsenopyrite *Gersdorffite Sulfosalts: *Pyrargyrite *Proustite *Tetrahedrite *Tennantite *Enargite *Bournonite * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canyon Diablo (meteorite)
The Canyon Diablo meteorite refers to the many fragments of the asteroid that created Meteor Crater (also called Barringer Crater), Arizona, United States. Meteorites have been found around the crater rim, and are named for nearby Canyon Diablo, which lies about three to four miles west of the crater. History The impactor fell about 50,000 years ago. Initially known and used by pre-historic Native Americans, Canyon Diablo meteorites have been collected and studied by the scientific community since the 19th century. Meteor Crater, from the late 19th to the early 20th century, was the center of a long dispute over the origin of craters that showed little evidence of volcanism. That debate was largely settled by the early 1930s, thanks to work by Daniel M. Barringer, F.R. Moulton, Harvey Harlow Nininger, and Eugene Shoemaker. In 1953, Clair Cameron Patterson measured ratios of the lead isotopes in samples of the meteorite. Through U-Pb radiometric dating, a refined estima ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Domenico Troili
Domenico Troili (1722–1792) was an Italian ''abbate'' and a Jesuit, who held the appointment of custodian of the library of the ruling family of Este in Modena. He is recognized as the first person who documented the fall of a meteorite, in 1766. Troili was a pupil of Roger Joseph Boscovich at the Collegio Romano, and supported his master's atomic theory explaining the properties of matter. The Albareto meteorite In 1766, Troili witnessed the fall of a stone from the sky near the town of Albareto, in the Duchy of Parma, Italy. He collected reports from many other eyewitnesses, closely examined the stone and detected in it small grains of a brassy mineral. He called the material "marchesita" (from Italian "little marchioness"). Troili summarized the results of his research in a 43-page document, ''Ragionamento della caduta di un sasso'' ("Concerning the fall of a stone from the air") published in Modena in 1766. The report by Troili said that at about five hours after midday, w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pearson Symbol
The Pearson symbol, or Pearson notation, is used in crystallography as a means of describing a crystal structure, and was originated by W. B. Pearson. The symbol is made up of two letters followed by a number. For example: * Diamond structure, ''cF''8 * Rutile structure, ''tP''6 The two (italicised) letters specify the Bravais lattice. The lower-case letter specifies the crystal family, and the upper-case letter the centering type. The number at the end of the Pearson symbol gives the number of the atoms in the conventional unit cell.Nomenclature of Inorganic Chemistry IUPAC Recommendations 2005 IR-3.4.4, pp. 49–51; IR-11.5, pp. 241–242. |
Space Group
In mathematics, physics and chemistry, a space group is the symmetry group of an object in space, usually in three dimensions. The elements of a space group (its symmetry operations) are the rigid transformations of an object that leave it unchanged. In three dimensions, space groups are classified into 219 distinct types, or 230 types if chiral copies are considered distinct. Space groups are discrete cocompact groups of isometries of an oriented Euclidean space in any number of dimensions. In dimensions other than 3, they are sometimes called Bieberbach groups. In crystallography, space groups are also called the crystallographic or Fedorov groups, and represent a description of the symmetry of the crystal. A definitive source regarding 3-dimensional space groups is the ''International Tables for Crystallography'' . History Space groups in 2 dimensions are the 17 wallpaper groups which have been known for several centuries, though the proof that the list was complete was only ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Albareto
Albareto (Parmigiano: ) is a ''comune'' (municipality) in the Province of Parma in the Italian region Emilia-Romagna, located about west of Bologna and about southwest of Parma. Albareto borders the following municipalities: Borgo Val di Taro, Compiano, Pontremoli, Sesta Godano, Tornolo, Varese Ligure, Zeri Zero Emissions Research and Initiatives (ZERI) was established by Gunter Pauli in 1994 at the United Nations University (UNU) with the support of the Japanese Government. Three years before the Kyoto Protocol was agreed upon in 1997, Pauli direct .... References External links Official website {{authority control Cities and towns in Emilia-Romagna ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Modena
Modena (, , ; egl, label=Emilian language#Dialects, Modenese, Mòdna ; ett, Mutna; la, Mutina) is a city and ''comune'' (municipality) on the south side of the Po Valley, in the Province of Modena in the Emilia-Romagna region of northern Italy. A town, and seat of an archbishop, it is known for its car industry since the factories of the famous Italian upper-class sports car makers Ferrari, De Tomaso, Lamborghini, Pagani (automobile), Pagani and Maserati are, or were, located here and all, except Lamborghini, have headquarters in the city or nearby. One of Ferrari's cars, the Ferrari 360, 360 Modena, was named after the town itself. Ferrari's production plant and Formula One team Scuderia Ferrari are based in Maranello south of the city. The University of Modena, founded in 1175 and expanded by Francesco II d'Este in 1686, focuses on economics, medicine and law, and is the second oldest :wikt:athenaeum, athenaeum in Italy. Italian military officers are trained at the Milit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mundrabilla (meteorite)
The Mundrabilla meteorite is an iron meteorite found in 1911 in Australia, one of the largest meteorites found, with a total known weight of 22 tonnes and the main mass (the single largest fragment) accounting for 12.4 tonnes. History In 1911 an iron meteorite fragment of 112 g was found by Harry Kent, foreman in charge of camels for the Western Australian survey of the transcontinental railway route, at , on Premier Downs station on the Nullarbor Plain. The small meteorite was called ''Premier Downs I''. Later in 1911 Kent found another small iron meteorite (116 g) about west from the found location of ''Premier Downs I'', named ''Premier Downs II''. Both meteorites were medium octahedrites, believed to be part of the same fall. In 1918 a third similar small iron meteorite of 99 g was found in the area by A. Ewing, named ''Premier Downs III''. In 1962 a small iron meteorite of 108 g with similar characteristics was found near Loongana railway station by a rabbit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrite
The mineral pyrite (), or iron pyrite, also known as fool's gold, is an iron sulfide with the chemical formula Iron, FeSulfur, S2 (iron (II) disulfide). Pyrite is the most abundant sulfide mineral. Pyrite's metallic Luster (mineralogy), luster and pale brass-yellow hue give it a superficial resemblance to gold, hence the well-known nickname of ''fool's gold''. The color has also led to the nicknames ''brass'', ''brazzle'', and ''Brazil'', primarily used to refer to pyrite found in coal. The name ''pyrite'' is derived from the Greek language, Greek (), 'stone or mineral which strikes fire', in turn from (), 'fire'. In ancient Roman times, this name was applied to several types of stone that would create sparks when struck against steel; Pliny the Elder described one of them as being brassy, almost certainly a reference to what we now call pyrite. By Georgius Agricola's time, , the term had become a generic term for all of the pyrite group, sulfide minerals. Pyrite is usua ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mineralogist
Mineralogy is a subject of geology specializing in the scientific study of the chemistry, crystal structure, and physical (including optical) properties of minerals and mineralized artifacts. Specific studies within mineralogy include the processes of mineral origin and formation, classification of minerals, their geographical distribution, as well as their utilization. History Early writing on mineralogy, especially on gemstones, comes from ancient Babylonia, the ancient Greco-Roman world, ancient and medieval China, and Sanskrit texts from ancient India and the ancient Islamic world. Books on the subject included the ''Naturalis Historia'' of Pliny the Elder, which not only described many different minerals but also explained many of their properties, and Kitab al Jawahir (Book of Precious Stones) by Persian scientist Al-Biruni. The German Renaissance specialist Georgius Agricola wrote works such as '' De re metallica'' (''On Metals'', 1556) and ''De Natura Fossilium'' (''O ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
