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Zakłodzie Meteorite
The Zakłodzie meteorite is a stony-iron meteorite found in Poland in 1998. Its mass is . It is composed predominantly from enstatite and meteoric iron. Currently classified as an ungrouped enstatite achondrite its classification is still an ongoing scientific debate. Naming and history The Zakłodzie meteorite was found beside a dirt road by Stanisław Jachymek who was searching for fossils and rocks. The site lies south of the village Zakłodzie (Lublin Voivodeship), after which the meteorite is named. A fireball, which may well have been the Zakłodzie meteorite, was seen in the area of the find on 21 April 1897; its weathering is consistent with such an age. part slices were on sale at /g. Mineralogy The meteorite is composed of 60% orthoenstatite, 20% meteoric iron, 10% troilite and 10% feldspar. Accessory minerals include schreibersite, oldhamite, alabandite, keilite and amphibole. The meteoric iron has a Nickel content of 16%. The mineral composition is similar to an e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enstatite Achondrite
Enstatite is a mineral; the magnesium endmember of the pyroxene silicate mineral series enstatite (MgSiO3) – ferrosilite (FeSiO3). The magnesium rich members of the solid solution series are common rock-forming minerals found in igneous and metamorphic rocks. The intermediate composition, , has historically been known as hypersthene, although this name has been formally abandoned and replaced by orthopyroxene. When determined petrographically or chemically the composition is given as relative proportions of enstatite (En) and ferrosilite (Fs) (e.g., En80Fs20). Polymorphs and varieties Most natural crystals are orthorhombic (space group P''bca'') although three polymorphs are known. The high temperature, low pressure polymorphs are protoenstatite and protoferrosilite (also orthorhombic, space group P''bcn'') while the low temperature forms, clinoenstatite and clinoferrosilite, are monoclinic (space group P2''1/c''). Weathered enstatite with a small amount of iron takes on a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oldhamite
Oldhamite is a calcium magnesium sulfide mineral with the chemical formula . Ferrous iron may also be present in the mineral resulting in the chemical formula . It is a pale to dark brown accessory mineral in meteorites. It crystallizes in the cubic crystal system, but typically occurs as Euhedral and anhedral, anhedral grains between other minerals. Discovery and occurrence It was first described in 1862 for an occurrence in the Bustee meteorite, Gorakhpur, Uttar Pradesh, India. It was named for Irish geologist Thomas Oldham (1816–1878), the Director of the Indian Geological Survey. It occurs as an interstitial mineral phase between silicate minerals in enstatite chondrite and achondrite meteorites. It occurs in association with enstatite, augite, niningerite, osbornite, troilite, gypsum and calcite. It has been reported from a variety of meteorite locations around the world including the Allan Hills 84001 meteorite of Antarctica. It has also been reported from a slag occurren ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quenched
In materials science, quenching is the rapid cooling of a workpiece in water, oil, polymer, air, or other fluids to obtain certain material properties. A type of heat treating, quenching prevents undesired low-temperature processes, such as phase transformations, from occurring. It does this by reducing the window of time during which these undesired reactions are both thermodynamically favorable, and kinetically accessible; for instance, quenching can reduce the crystal grain size of both metallic and plastic materials, increasing their hardness. In metallurgy, quenching is most commonly used to harden steel by inducing a martensite transformation, where the steel must be rapidly cooled through its eutectoid point, the temperature at which austenite becomes unstable. In steel alloyed with metals such as nickel and manganese, the eutectoid temperature becomes much lower, but the kinetic barriers to phase transformation remain the same. This allows quenching to start at a lowe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enstatite Achondrites
Enstatite is a mineral; the magnesium endmember of the pyroxene silicate mineral series enstatite (MgSiO3) – ferrosilite (FeSiO3). The magnesium rich members of the solid solution series are common rock-forming minerals found in igneous and metamorphic rocks. The intermediate composition, , has historically been known as hypersthene, although this name has been formally abandoned and replaced by orthopyroxene. When determined petrographically or chemically the composition is given as relative proportions of enstatite (En) and ferrosilite (Fs) (e.g., En80Fs20). Polymorphs and varieties Most natural crystals are orthorhombic (space group P''bca'') although three polymorphs are known. The high temperature, low pressure polymorphs are protoenstatite and protoferrosilite (also orthorhombic, space group P''bcn'') while the low temperature forms, clinoenstatite and clinoferrosilite, are monoclinic (space group P2''1/c''). Weathered enstatite with a small amount of iron takes on a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Keilite
Keilite is an iron-magnesium sulfide mineral with the chemical formula that is found in enstatite chondrites. Keilite is the iron-dominant analog of niningerite. Keilite is named after Klaus Keil (born 1934). Occurrences Examples of keilite occurrences are enstatite chondrite Enstatite chondrites (E-type chondrites) are a rare form of meteorite, rich in the mineral enstatite. Only about 200 E-Type chondrites are currently known, comprising about 2% of the chondrites that fall on Earth.Norton, O.R. and Chitwood, L.A. F ...s and the Zakłodzie meteorite. It appears to be confined to impact-melt influenced enstatite chondrites that were quenched. There are also some meteorites interpreted as impact-melt breccias that don't contain keilite. This is explained as a deeper burial after impact, which slowed cooling and enabled retrograde reactions (diapthoresis) to take place. References Galena group Iron(II) minerals Magnesium minerals Cubic minerals Minerals in space group 2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NWA 4301
NWA or Nwa most commonly refers to: * N.W.A ("Niggaz Wit Attitudes"), a hip hop group from Compton, California, US * National Wrestling Alliance, a professional wrestling organization NWA or Nwa may refer to: Music * New Weird America, a subgenre of psychedelic and indie music, popularized in the '60s and '70s Places * Nwa, Kale, a village in Burma * Nwa, Cameroon, a commune in Donga-Mantung, Cameroon * North Waziristan, an administrative region in Pakistan * Northwest Arkansas, the Fayetteville–Springdale–Rogers metropolitan region of the U.S. state of Arkansas Organizations * Northwest Airlines (ICAO code), a defunct U.S. airline * North-Western Area Command (RAAF), a defunct Royal Australian Air Force command * National Weather Association, a U.S. meteorological society * Neighborhood watch association, see neighborhood watch * Nelson Weavers' Association, defunct British trade union * New Women's Association, a Japanese women's rights organization (1919-1922) * Nuer Whi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aubrite
Aubrites are a group of meteorites named for Aubres, a small achondrite meteorite that fell near Nyons, France, in 1836. They are primarily composed of the orthopyroxene enstatite and are often called enstatite achondrites. Their igneous origin separates them from primitive enstatite achondrites and means they originated in an asteroid. Aubrites are typically light-colored with a brownish fusion crust. Most aubrites are heavily brecciated; they are often said to look "lunar" in origin. Aubrites are primarily composed of large white crystals of the Fe-poor, Mg-rich orthopyroxene, or enstatite, with minor phases of olivine, nickel-iron metal, and troilite, indicating a magmatic formation under extremely reducing conditions. The severe brecciation of most aubrites attests to a violent history for their parent body. Since some aubrites contain chondritic xenoliths, it is likely that the aubrite parent body collided with an asteroid of “F-chondritic” composition. Comparisons of au ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Type Locality (geology)
Type locality, also called type area, is the locality where a particular rock type, stratigraphic unit or mineral species is first identified. If the stratigraphic unit in a locality is layered, it is called a stratotype, whereas the standard of reference for unlayered rocks is the type locality. The term is similar to the term type site in archaeology or the term type specimen in biology. Examples of geological type localities Rocks and minerals * Aragonite: Molina de Aragón, Guadalajara, Spain * Autunite: Autun, France * Benmoreite: Ben More (Mull), Scotland * Blairmorite: Blairmore, Alberta, Canada * Boninite: Bonin Islands, Japan * Comendite: Comende, San Pietro Island, Sardinia * Cummingtonite: Cummington, Massachusetts * Dunite: Dun Mountain, New Zealand. * Essexite: Essex County, Massachusetts, US * Fayalite: Horta, Fayal Island, Azores, Portugal * Harzburgite: Bad Harzburg, Germany * Icelandite: Thingmuli (Þingmúli), Iceland * Ijolite: Iivaara, Kuusamo, Finl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chondrules
A chondrule (from Ancient Greek χόνδρος ''chondros'', grain) is a round grain found in a chondrite. Chondrules form as molten or partially molten droplets in space before being accreted to their parent asteroids. Because chondrites represent one of the oldest solid materials within the Solar System and are believed to be the building blocks of the planetary system, it follows that an understanding of the formation of chondrules is important to understand the initial development of the planetary system. Abundance and size Different kinds of the stony, non-metallic meteorites called chondrites contain different fractions of chondrules (see table below). In general, carbonaceous chondrites contain the smallest percentage (by volume) of chondrules, including the CI chondrites which, paradoxically, do not contain ''any'' chondrules despite their designation as chondrites, whereas ordinary and enstatite chondrites contain the most. Because ordinary chondrites represent 80% o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enstatite Chondrite
Enstatite chondrites (E-type chondrites) are a rare form of meteorite, rich in the mineral enstatite. Only about 200 E-Type chondrites are currently known, comprising about 2% of the chondrites that fall on Earth.Norton, O.R. and Chitwood, L.A. Field Guide to Meteors and Meteorites, Springer-Verlag, London 2008 There are two main subtypes: EH and EL, classified based on their iron content. Origin E-type chondrites are among the most chemically redox, reduced rocks known, with most of their iron taking the form of metal or sulfide rather than an oxide. They tend to be high in the mineral enstatite (MgSiO3), from which they derive their name. Based on spectral analysis, it has been suggested that the asteroid 16 Psyche may be the common parent for this type of meteorite. Composition Unlike most other chondrites, the minerals in enstatite chondrites contain almost no iron oxide; they are the most oxygen-poor silicate rocks known. They were supposed to be the driest objects in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
