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Pentlandite
Pentlandite is an iron–nickel sulfide with the chemical formula . Pentlandite has a narrow variation range in Ni:Fe but it is usually described as having a Ni:Fe of 1:1. It also contains minor cobalt, usually at low levels as a fraction of weight. Pentlandite forms isometric crystals, but it is normally found in massive granular aggregates. It is brittle with a hardness of 3.5–4 and specific gravity of 4.6–5.0 and is non-magnetic. It has a yellowish bronze color. Pentlandite is the most important source of mined nickel. Name and discovery It is named after the Irish scientist Joseph Barclay Pentland (1797–1873), who first noted the mineral. Paragenesis Pentlandite is the most common terrestrial nickel sulfide. It typically forms during cooling of a sulfide melt. These sulfide melts, in turn, are typically formed during the evolution of a silicate melt. Because Ni is a chalcophile-like element, it has preference for (i.e. it "partitions into") sulfide phases. In sul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nickel
Nickel is a chemical element with symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel is a hard and ductile transition metal. Pure nickel is chemically reactive but large pieces are slow to react with air under standard conditions because a passivation layer of nickel oxide forms on the surface that prevents further corrosion. Even so, pure native nickel is found in Earth's crust only in tiny amounts, usually in ultramafic rocks, and in the interiors of larger nickel–iron meteorites that were not exposed to oxygen when outside Earth's atmosphere. Meteoric nickel is found in combination with iron, a reflection of the origin of those elements as major end products of supernova nucleosynthesis. An iron–nickel mixture is thought to compose Earth's outer and inner cores. Use of nickel (as natural meteoric nickel–iron alloy) has been traced as far back as 3500 BCE. Nickel was first isolated and classified a ... [...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 * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrrhotite
Pyrrhotite is an iron sulfide mineral with the formula Fe(1-x)S (x = 0 to 0.2). It is a nonstoichiometric variant of FeS, the mineral known as troilite. Pyrrhotite is also called magnetic pyrite, because the color is similar to pyrite and it is weakly magnetic. The magnetism decreases as the iron content increases, and troilite is non-magnetic.Vaughan, D. J.; Craig, J. R. "Mineral Chemistry of Metal Sulfides" Cambridge University Press, Cambridge: 1978. . Structure Pyrrhotite exists as a number of polytypes of hexagonal or monoclinic crystal symmetry; several polytypes often occur within the same specimen. Their structure is based on the NiAs unit cell. As such, Fe occupies an octahedral site and the sulfide centers occupy trigonal prismatic sites. Materials with the NiAs structure often are non-stoichiometric because they lack up to 1/8th fraction of the metal ions, creating vacancies. One of such structures is pyrrhotite-4C (Fe7S8). Here "4" indicates that iron vacan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfide
Sulfide (British English also sulphide) is an inorganic anion of sulfur with the chemical formula S2− or a compound containing one or more S2− ions. Solutions of sulfide salts are corrosive. ''Sulfide'' also refers to chemical compounds large families of inorganic and organic compounds, e.g. lead sulfide and dimethyl sulfide. Hydrogen sulfide (H2S) and bisulfide (SH−) are the conjugate acids of sulfide. Chemical properties The sulfide ion, S2−, does not exist in aqueous alkaline solutions of Na2S. Instead sulfide converts to hydrosulfide: :S2− + H2O → SH− + OH− Upon treatment with an acid, sulfide salts convert to hydrogen sulfide: :S2− + H+ → SH− :SH− + H+ → H2S Oxidation of sulfide is a complicated process. Depending on the conditions, the oxidation can produce elemental sulfur, polysulfides, polythionates, sulfite, or sulfate. Metal sulfides react with halogens, forming sulfur and metal salts. :8 MgS + 8 I2 → S8 + ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iron
Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in front of oxygen (32.1% and 30.1%, respectively), forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust. In its metallic state, iron is rare in the Earth's crust, limited mainly to deposition by meteorites. Iron ores, by contrast, are among the most abundant in the Earth's crust, although extracting usable metal from them requires kilns or furnaces capable of reaching or higher, about higher than that required to smelt copper. Humans started to master that process in Eurasia during the 2nd millennium BCE and the use of iron tools and weapons began to displace copper alloys, in some regions, only around 1200 BCE. That event is considered the transition from the Bronze Age to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Joseph Barclay Pentland
Joseph Barclay Pentland (17 January 1797 in ''Dictionary of Ulster Biography'' – 12 July 1873) was an Irish geographer, natural scientist, and traveller. Born in Ballybofey ( County Donegal, Ireland), Pentland was educated at |
Partition Coefficient
In the physical sciences, a partition coefficient (''P'') or distribution coefficient (''D'') is the ratio of concentrations of a compound in a mixture of two immiscible solvents at equilibrium. This ratio is therefore a comparison of the solubilities of the solute in these two liquids. The partition coefficient generally refers to the concentration ratio of un-ionized species of compound, whereas the distribution coefficient refers to the concentration ratio of all species of the compound (ionized plus un-ionized). In the chemical and pharmaceutical sciences, both phases usually are solvents. Most commonly, one of the solvents is water, while the second is hydrophobic, such as 1-octanol. Hence the partition coefficient measures how hydrophilic ("water-loving") or hydrophobic ("water-fearing") a chemical substance is. Partition coefficients are useful in estimating the distribution of drugs within the body. Hydrophobic drugs with high octanol-water partition coefficients are ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Igneous Differentiation
In geology, igneous differentiation, or magmatic differentiation, is an umbrella term for the various processes by which magmas undergo bulk chemical change during the partial melting process, cooling, emplacement, or eruption. The sequence of (usually increasingly silicic) magmas produced by igneous differentiation is known as a magma series. Definitions Primary melts When a rock melts to form a liquid, the liquid is known as a ''primary melt''. Primary melts have not undergone any differentiation and represent the starting composition of a magma. In nature, primary melts are rarely seen. Some leucosomes of migmatites are examples of primary melts. Primary melts derived from the mantle are especially important and are known as ''primitive melts'' or primitive magmas. By finding the primitive magma composition of a magma series, it is possible to model the composition of the rock from which a melt was formed, which is important because we have little direct evidence of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monosulfide Solid Solution , chemical compound with the formula US
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Monosulfide may refer to: * Carbon monosulfide, chemical compound with the formula CS * Copper monosulfide, chemical compound with the formula CuS * Mononitrogen monosulfide, inorganic compound with the formula SN * Silicon monosulfide, chemical compound with the formula SiS * Scandium monosulfide, chemical compound of scandium and sulfur with the chemical formula ScS * Uranium monosulfide Uranium monosulfide is an inorganic chemical compound of uranium and sulfur Sulfur (or sulphur in British English) is a chemical element with the symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exsolution
A solid solution, a term popularly used for metals, is a homogenous mixture of two different kinds of atoms in solid state and have a single crystal structure. Many examples can be found in metallurgy, geology, and solid-state chemistry. The word "solution" is used to describe the intimate mixing of components at the atomic level and distinguishes these homogeneous materials from physical mixtures of components. Two terms are mainly associated with solid solutions - ''solvents'' and ''solutes,'' depending on the relative abundance of the atomic species. In general if two compounds are isostructural then a solid solution will exist between the end members (also known as parents). For example sodium chloride and potassium chloride have the same cubic crystal structure so it is possible to make a pure compound with any ratio of sodium to potassium (Na1-xKx)Cl by dissolving that ratio of NaCl and KCl in water and then evaporating the solution. A member of this family is sold under t ... [...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 Fe S2 (iron (II) disulfide). Pyrite is the most abundant sulfide mineral. Pyrite's metallic 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 (), '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 sulfide minerals. Pyrite is usually found associated with other sulfides or oxides in quartz ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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