IAB Meteorites
IAB meteorites are a group of iron meteorites according to their overall composition and a group of primitive achondrites because of silicate inclusions that show a strong affinity to winonaites and chondrites. Description The IAB meteorites are composed of meteoric iron (kamacite and taenite) and silicate inclusions. Structurally they can be hexahedrites, fine to coarse octahedrites, or even ataxites. Most of them are octahedrite with medium to coarse taenite-lamella and distinct Widmanstätten patterning. The silicate inclusions are composed of low-Ca pyroxene, high-Ca pyroxene, olivine, plagioclase, troilite, graphite, different phosphates, meteoric iron and traces of daubréelite and chromite. This composition is very similar to the composition of winonaites, and it is therefore argued that the two groups share the same parent body. There are also similarities with the IIICD meteorites, but it is not yet clear whether they are also part of that parent body. Classification T ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Goose Lake Meteorite
The Goose Lake meteorite is a meteorite that was found at Goose Lake in the United States by two hunters from Oakland, California on October 13, 1938. In 1939 it was acquired by the United States National Museum. From 1939 until January 14, 1941 it was on exhibition at the Golden Gate International Exposition before moving to Washington, D.C. It was placed on display in the National Museum's meteorite hall until that hall was closed in the 1950s. Today, the meteorite is on display at the National Museum of Natural History. No crater was left on the ground where it was found, thus meaning that the velocity of the meteorite's impact was minimal. See also * Glossary of meteoritics This is a glossary of terms used in meteoritics, the science of meteorites. # * 2 Pallas – an asteroid from the asteroid belt and one of the likely parent bodies of the CR meteorites. * 4 Vesta – second-largest asteroid in the asteroid b ... References {{Meteorites by name Meteorites fo ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Octahedrite
Octahedrites are the most common structural class of iron meteorites. The structures occur because the meteoric iron has a certain nickel concentration that leads to the exsolution of kamacite out of taenite while cooling. Structure Octahedrites derive their name from the crystal structure paralleling an octahedron. Opposite faces are parallel so, although an octahedron has 8 faces, there are only 4 sets of kamacite plates. Due to a long cooling time in the interior of the parent asteroids, these alloys have crystallized into intermixed millimeter-sized bands (from about 0.2 mm to 5 cm). When polished and acid etched the classic Widmanstätten patterns of intersecting lines of lamellar kamacite, are visible. In gaps between the kamacite and taenite lamellae, a fine-grained mixture called plessite is often found. An iron nickel phosphide, schreibersite, is present in most nickel-iron meteorites, as well as an iron-nickel-cobalt carbide, cohenite. Graphite and troili ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Nantan Meteorite
The Nantan meteorite is an iron meteorite that belongs to the IAB group and the MG (main group) subgroup. In 2000, pieces of the meteorite were included in an art installation for The BullRing Shopping Centre in Birmingham, England. A plaque now commemorates the occasion. , pieces of Nantan meteorite were on sale at /g. Discovery The fall of the meteorite might have been observed in 1516, but it is difficult to assess if this event is connected with the pieces that were retrieved in 1958. The meteorite burst during passage through the atmosphere and the pieces were scattered in a strewn field long and wide near the city of Nantan, Nandan County, Guangxi (China). The meteorite was named after the city. The fragments were not retrieved until the 1950s when they were gathered for smelting to make metal for the growing industrialization of China. It was found that the meteoric iron contained too much nickel for smelting. Description and Classification The Nantan meteorite was ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Monturaqui
Monturaqui is an impact crater in Chile. It lies south of the Salar de Atacama and was formed 663,000 ± 90,000 years ago by the impact of an IAB meteorite. It is wide and deep and contains a salt pan. Only a few remnants of the meteorite that formed the crater have been collected, with most of the rocks being of local origin. The crater was discovered in 1962 and identified as an impact crater in 1966. Human history The crater was first suspected to be an impact crater in 1962, when it was found on aerial images. After geologic research on the site found evidence of the impact event, it was identified as an impact crater in 1966. The crater has not been drilled. Its name is derived from the mountain range where it is located and from the town of Monturaqui . The closest town is Peine, northeast of the crater. An old Inka road, which goes from the Pacific Ocean to San Pedro de Atacama and further to Argentina, runs from the crater. The crater has been deemed by Stanisl ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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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]   |
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IIICD Meteorites
IIICD meteorites are a group of primitive achondrites. They are classified in a clan together with the IAB meteorites and the winonaites. Description IIICD meteorites consists dominantly of meteoric iron with silicate inclusions. The silicate inclusions are almost identical to the IAB meteorite inclusions. They contain low-Ca pyroxene, high-Ca pyroxene, olivine, plagioclase, troilite, graphite, different phosphates, meteoric iron and traces of daubréelite and chromite. Parent body It has been established that IAB meteorites and winonaites originated from the same parent body. The same is not yet clear for IIICD meteorites, that originated from the same or a very similar asteroid. Classification The IIICD meteorites are classified as primitive achondrites because they have silicate inclusions and show signs of partial melting. The silicate inclusion are almost identical to silicate inclusions in IAB meteorites, and both are very similar to winonaites. For this reason all t ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Chromite
Chromite is a crystalline mineral composed primarily of iron(II) oxide and chromium(III) oxide compounds. It can be represented by the chemical formula of FeCr2O4. It is an oxide mineral belonging to the spinel group. The element magnesium can substitute for iron in variable amounts as it forms a solid solution with magnesiochromite (MgCr2O4). A substitution of the element aluminium can also occur, leading to hercynite (FeAl2O4). Chromite today is mined particularly to make stainless steel through the production of ferrochrome (FeCr), which is an iron-chromium alloy. Chromite grains are commonly found in large mafic igneous intrusions such as the Bushveld in South Africa and India. Chromite is iron-black in color with a metallic luster, a dark brown streak and a hardness on the Mohs scale of 5.5. Properties Chromite minerals are mainly found in mafic-ultramafic igneous intrusions and are also sometimes found in metamorphic rocks. The chromite minerals occur in layered format ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Daubréelite
Daubréelite is a rare sulfide mineral. It crystallizes with cubic symmetry and has chemical composition of Fe2+Cr3+2S4. It usually occurs as black platy aggregates. Naming and history Daubréelite was named after the French mineralogist, petrologist and meteoriticist Gabriel Auguste Daubrée. The mineral was first described in 1876 in the ''American Journal of Science''. Its type locality is the Coahuila meteorite, Bolsom de Mapimí, Coahuila, Mexico. Classification In the Nickel-Strunz classification daubréelite is part of the "Sulfides and Sulfosalts" and further a "metal sulfide with a metal-sulfide ratio of 3:4 and 2:3". Occurrences Daubréelite is found in iron meteorites as an inclusion in meteoric iron (kamacite and taenite). Further paragenetic minerals are alabandine, enstatite, graphite, plagioclase and schreibersite. According to one source daubréelite has been described from 34 localities. Some notable examples being the ALH 84001 meteorite, Hoba meteorite, a ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Graphite
Graphite () is a crystalline form of the element carbon. It consists of stacked layers of graphene. Graphite occurs naturally and is the most stable form of carbon under standard conditions. Synthetic and natural graphite are consumed on large scale (300 kton/year, in 1989) for uses in pencils, lubricants, and electrodes. Under high pressures and temperatures it converts to diamond. It is a weak conductor of heat and electricity. Types and varieties Natural graphite The principal types of natural graphite, each occurring in different types of ore deposits, are * Crystalline small flakes of graphite (or flake graphite) occurs as isolated, flat, plate-like particles with hexagonal edges if unbroken. When broken the edges can be irregular or angular; * Amorphous graphite: very fine flake graphite is sometimes called amorphous; * Lump graphite (or vein graphite) occurs in fissure veins or fractures and appears as massive platy intergrowths of fibrous or acicular crystalline ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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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]   |
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Plagioclase
Plagioclase is a series of tectosilicate (framework silicate) minerals within the feldspar group. Rather than referring to a particular mineral with a specific chemical composition, plagioclase is a continuous solid solution series, more properly known as the plagioclase feldspar series. This was first shown by the German mineralogist Johann Friedrich Christian Hessel (1796–1872) in 1826. The series ranges from albite to anorthite endmembers (with respective compositions NaAlSi3O8 to CaAl2Si2O8), where sodium and calcium atoms can substitute for each other in the mineral's crystal lattice structure. Plagioclase in hand samples is often identified by its polysynthetic crystal twinning or 'record-groove' effect. Plagioclase is a major constituent mineral in the Earth's crust, and is consequently an important diagnostic tool in petrology for identifying the composition, origin and evolution of igneous rocks. Plagioclase is also a major constituent of rock in the highlan ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Olivine
The mineral olivine () is a magnesium iron silicate with the chemical formula . It is a type of nesosilicate or orthosilicate. The primary component of the Earth's upper mantle, it is a common mineral in Earth's subsurface, but weathers quickly on the surface. For this reason, olivine has been proposed as a good candidate for accelerated weathering to sequester carbon dioxide from the Earth's oceans and atmosphere, as part of climate change mitigation. Olivine also has many other historical uses, such as the gemstone peridot (or chrysolite), as well as industrial applications like metalworking processes. The ratio of magnesium to iron varies between the two endmembers of the solid solution series: forsterite (Mg-endmember: ) and fayalite (Fe-endmember: ). Compositions of olivine are commonly expressed as molar percentages of forsterite (Fo) and fayalite (Fa) (''e.g.'', Fo70Fa30). Forsterite's melting temperature is unusually high at atmospheric pressure, almost , while ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |