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Magnetite
Magnetite is a mineral and one of the main iron ores, with the chemical formula . It is one of the iron oxide, oxides of iron, and is ferrimagnetism, ferrimagnetic; it is attracted to a magnet and can be magnetization, magnetized to become a permanent magnet itself. With the exception of extremely rare native iron deposits, it is the most magnetic of all the naturally occurring minerals on Earth. Naturally magnetized pieces of magnetite, called lodestone, will attract small pieces of iron, which is how ancient peoples first discovered the property of magnetism. Magnetite is black or brownish-black with a metallic luster, has a Mohs scale of mineral hardness, Mohs hardness of 5–6 and leaves a black streak (mineralogy), streak. Small grains of magnetite are very common in igneous rocks, igneous and metamorphic rocks. The chemical IUPAC name is iron(II,III) oxide and the common chemical name is ''ferrous-ferric oxide''. Properties In addition to igneous rocks, magnetite als ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetite Sample With Neodymium Magnet
Magnetite is a mineral and one of the main iron ores, with the chemical formula . It is one of the oxides of iron, and is ferrimagnetic; it is attracted to a magnet and can be magnetized to become a permanent magnet itself. With the exception of extremely rare native iron deposits, it is the most magnetic of all the naturally occurring minerals on Earth. Naturally magnetized pieces of magnetite, called lodestone, will attract small pieces of iron, which is how ancient peoples first discovered the property of magnetism. Magnetite is black or brownish-black with a metallic luster, has a Mohs hardness of 5–6 and leaves a black streak. Small grains of magnetite are very common in igneous and metamorphic rocks. The chemical IUPAC name is iron(II,III) oxide and the common chemical name is ''ferrous-ferric oxide''. Properties In addition to igneous rocks, magnetite also occurs in sedimentary rocks, including banded iron formations and in lake and marine sediments as both de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iron Ore
Iron ores are rocks and minerals from which metallic iron can be economically extracted. The ores are usually rich in iron oxides and vary in color from dark grey, bright yellow, or deep purple to rusty red. The iron is usually found in the form of magnetite (, 72.4% Fe), hematite (, 69.9% Fe), goethite (, 62.9% Fe), limonite (, 55% Fe), or siderite (, 48.2% Fe). Ores containing very high quantities of hematite or magnetite (typically greater than about 60% iron) are known as natural ore or irect shipping ore and can be fed directly into iron-making blast furnaces. Iron ore is the raw material used to make pig iron, which is one of the main raw materials to make steel — 98% of the mined iron ore is used to make steel. In 2011 the ''Financial Times'' quoted Christopher LaFemina, mining analyst at Barclays Capital, saying that iron ore is "more integral to the global economy than any other commodity, except perhaps oil". Sources Elemental iron is virtually absent o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iron(II,III) Oxide
Iron(II,III) oxide, or black iron oxide, is the chemical compound with formula Fe3O4. It occurs in nature as the mineral magnetite. It is one of a number of iron oxides, the others being iron(II) oxide (FeO), which is rare, and iron(III) oxide (Fe2O3) which also occurs naturally as the mineral hematite. It contains both Fe2+ and Fe3+ ions and is sometimes formulated as FeO ∙ Fe2O3. This iron oxide is encountered in the laboratory as a black powder. It exhibits permanent magnetism and is Ferrimagnetism, ferrimagnetic, but is sometimes incorrectly described as Ferromagnetism, ferromagnetic. Its most extensive use is as a black pigment (see: Mars Black (pigment), Mars Black). For this purpose, it is synthesized rather than being extracted from the naturally occurring mineral as the particle size and shape can be varied by the method of production. Preparation Heated iron metal interacts with steam to form iron oxide and hydrogen gas. :3Fe + 4H2O->Fe3O4 + 4H2 Under Hypox ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetofossils
Magnetofossils are the fossil remains of magnetic particles produced by magnetotactic bacteria (magnetobacteria) and preserved in the geologic record. The oldest definitive magnetofossils formed of the mineral magnetite come from the Cretaceous chalk beds of southern England, while magnetofossil reports, not considered to be robust, extend on Earth to the 1.9-billion-year-old Gunflint Chert; they may include the four-billion-year-old Martian meteorite ALH84001. Magnetotactic organisms are prokaryotic, with only one example of giant magnetofossils, likely produced by eukaryotic organisms, having been reported. Magnetotactic bacteria, the source of the magnetofossils, are magnetite (Fe3O4) or greigite (Fe3S4) producing bacteria found in both freshwater and marine environments. These magnetite bearing magnetotatic bacteria are found in the oxic-anoxic transition zone where conditions are such that oxygen levels are less than those found in the atmosphere (microaerophilic). Comp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Banded Iron Formation
Banded iron formations (BIFs; also called banded ironstone formations) are distinctive units of sedimentary rock consisting of alternating layers of iron oxides and iron-poor chert. They can be up to several hundred meters in thickness and extend laterally for several hundred kilometers. Almost all of these formations are of Precambrian age and are thought to record the Great Oxygenation Event, oxygenation of the Earth's oceans. Some of the Earth's oldest rock formations, which formed about (Year#SI prefix multipliers, Ma), are associated with banded iron formations. Banded iron formations are thought to have formed in sea water as the result of oxygen production by photosynthesis, photosynthetic cyanobacteria. The oxygen combined with dissolved iron in Earth's oceans to form insoluble iron oxides, which precipitated out, forming a thin layer on the ocean floor. Each band is similar to a varve, resulting from cyclic variations in oxygen production. Banded iron formations we ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maghemite
Maghemite (Fe2O3, γ-Fe2O3) is a member of the family of iron oxides. It has the same formula as hematite, but the same spinel ferrite structure as magnetite () and is also ferrimagnetic. It is sometimes spelled as "maghaemite". ''Maghemite'' can be considered as an Fe(II)-deficient magnetite with formula \left(\ce\right)_A\left ce\rightB\ce where \square represents a vacancy, A indicates tetrahedral and B octahedral positioning. Occurrence Maghemite forms by weathering or low-temperature oxidation of spinels containing iron(II) such as magnetite or titanomagnetite. Maghemite can also form through dehydration and transformation of certain iron oxyhydroxide minerals, such as lepidocrocite and ferrihydrite. It occurs as widespread brown or yellow pigment in terrestrial sediments and soils. It is associated with magnetite, ilmenite, anatase, pyrite, marcasite, lepidocrocite and goethite. It is known to also form in areas that have been subjected to bushfires (particularly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lodestone
Lodestones are naturally magnetization, magnetized pieces of the mineral magnetite. They are naturally occurring magnets, which can attract iron. The property of magnetism was first discovered in Ancient history, antiquity through lodestones. Pieces of lodestone, suspended so they could turn, were the first magnetic compasses, and their importance to early navigation is indicated by the name ''lodestone'', which in Middle English means "course stone" or "leading stone", from the now-obsolete meaning of '':wikt:lode, lode'' as "journey, way". Lodestone is one of only a very few minerals that is found naturally magnetized. Magnetite is black or brownish-black, with a metallic lustre (mineralogy), luster, a Mohs scale of mineral hardness, Mohs hardness of 5.5–6.5 and a black streak (mineralogy), streak. Origin The process by which lodestone is created has long been an open question in geology. Only a small amount of the magnetite on the Earth is found magnetized as lodest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnet
A magnet is a material or object that produces a magnetic field. This magnetic field is invisible but is responsible for the most notable property of a magnet: a force that pulls on other ferromagnetic materials, such as iron, steel, nickel, cobalt, etc. and attracts or repels other magnets. A permanent magnet is an object made from a material that is magnetized and creates its own persistent magnetic field. An everyday example is a refrigerator magnet used to hold notes on a refrigerator door. Materials that can be magnetized, which are also the ones that are strongly attracted to a magnet, are called ferromagnetic (or ferrimagnetic). These include the elements iron, nickel and cobalt and their alloys, some alloys of rare-earth metals, and some naturally occurring minerals such as lodestone. Although ferromagnetic (and ferrimagnetic) materials are the only ones attracted to a magnet strongly enough to be commonly considered magnetic, all other substances respond weakly to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mineral
In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid substance with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. (2011): Minerals'; p. 1. In the series ''Geology: Landforms, Minerals, and Rocks''. Rosen Publishing Group. The Geology, geological definition of mineral normally excludes compounds that occur only in living organisms. However, some minerals are often biogenic (such as calcite) or organic compounds in the sense of chemistry (such as mellite). Moreover, living organisms often synthesize inorganic minerals (such as hydroxylapatite) that also occur in rocks. The concept of mineral is distinct from rock (geology), rock, which is any bulk solid geologic material that is relatively homogeneous at a large enough scale. A rock may consist of one type of mineral or may be an aggregate (geology), aggregate of two or more different types of minerals, spaci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ferrimagnetism
A ferrimagnetic material is a material that has populations of atoms with opposing magnetic moments, as in antiferromagnetism, but these moments are unequal in magnitude, so a spontaneous magnetization remains. This can for example occur when the populations consist of different atoms or ions (such as Fe2+ and Fe3+). Like ferromagnetic substances, ferrimagnetic substances are attracted by magnets and can be magnetized to make permanent magnets. The oldest known magnetic substance, magnetite (Fe3O4), is ferrimagnetic, but was classified as a ferromagnet before Louis Néel discovered ferrimagnetism in 1948. Since the discovery, numerous uses have been found for ferrimagnetic materials, such as hard-drive platters and biomedical applications. History Until the twentieth century, all naturally occurring magnetic substances were called ferromagnets. In 1936, Louis Néel published a paper proposing the existence of a new form of cooperative magnetism he called antiferro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iron Oxide
An iron oxide is a chemical compound composed of iron and oxygen. Several iron oxides are recognized. Often they are non-stoichiometric. Ferric oxyhydroxides are a related class of compounds, perhaps the best known of which is rust. Iron oxides and oxyhydroxides are widespread in nature and play an important role in many geological and biological processes. They are used as iron ores, pigments, catalysts, and in thermite, and occur in hemoglobin. Iron oxides are inexpensive and durable pigments in paints, coatings and colored concretes. Colors commonly available are in the " earthy" end of the yellow/orange/red/brown/black range. When used as a food coloring, it has E number E172. Stoichiometries Iron oxides feature as ferrous ( Fe(II)) or ferric ( Fe(III)) or both. They adopt octahedral or tetrahedral coordination geometry. Only a few oxides are significant at the earth's surface, particularly wüstite, magnetite, and hematite. * Oxides of FeII ** FeO: ir ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
