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Stony–iron Meteorite
Stony-iron meteorites or siderolites are meteorites that consist of nearly equal parts of meteoric iron and Silicate mineral, silicates. This distinguishes them from the stony meteorites, that are mostly silicates, and the iron meteorites, that are mostly meteoric iron. Stony-iron meteorites are all differentiated, meaning that they show signs of alteration. They are therefore achondrites. The stony-irons are divided into mesosiderites and pallasites. Pallasites have a matrix of meteoric iron with embedded silicates (most of it olivine). Mesosiderites are breccias which show signs of metamorphism. The meteoric iron occurs in clasts instead of a matrix.Karl K. Turekian. ''Meteorites, comets, and planets'112/ref> They are in the top rank of all Meteorite classification schemes, usually called "Type". Mineralogy The meteoric iron of stony-irons is similar to that of iron meteorites, consisting mostly of kamacite and taenite in different proportions. The silicates are dominated by o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Esquel (meteorite)
__NOTOC__ Esquel is a meteorite found near Esquel, a Patagonian town in the northwest part of the provinces of Argentina, province of Chubut Province, Chubut in Argentina. It is a pallasite, a type of stony–iron meteorite that when cut and polished shows yellowish olivine (peridot) crystals. In 1951 a farmer uncovered a meteorite in an unknown location near Esquel while digging a hole for a water tank. The meteorite was purchased from the finders and taken to the United States in 1992 by meteorite expert Robert A. Haag, Robert Haag. The Esquel pallasite is known worldwide among collectors and the meteoritical scientific community. Esquel is regarded as one of the most beautiful meteorites ever found and is also one of the most desirable pallasites among meteorite collectors. It is a main group pallasite (MGP). Specimens The Meteoritical Bulletin no. 29 (1964) reports a main mass of "about 1500 kg". However O. A. Turone claimed a main mass weight of ."The weight of the main m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carlsbergite
Carlsbergite is a nitride mineral that has the chemical formula CrN, or chromium nitride. It is named after the Carlsberg Foundation which backed the recovery of the Agpalilik fragment of the Cape York meteorite in which the mineral was first described. It occurs in meteorites along the grain boundaries of kamacite (nickel-rich native iron) or troilite (FeS: iron sulfide) in the form of tiny plates. It occurs associated with kamacite, taenite, daubreelite, troilite and sphalerite, . In addition to the Cape York meteorite, carlsbergite has been reported from: * the North Chile meteorite in the Antofagasta Province, Chile * the Nentmannsdorf meteorite of Bahretal, Saxony, Germany * the Okinawa Trough, Senkaku Islands, Okinawa Prefecture, Japan * the Uwet meteorite of Cross River State, Nigeria * the Sikhote-Alin meteorite, Sikhote-Alin Mountains, Russia * the Hex River Mountains meteorite from the Cape Winelands District, Western Cape Province, South Africa * the Canyon Diablo m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tridymite
Tridymite is a high-temperature polymorphism (materials science), polymorph of silica and usually occurs as minute tabular white or colorless pseudo-hexagonal crystals, or scales, in cavities in felsic volcanic rocks. Its chemical formula is silicon, Sioxygen, O2. Tridymite was first described in 1868 and the Type locality (geology), type location is in Hidalgo, Mexico. The name is from the Greek (language), Greek ''tridymos'' for ''triplet'' as tridymite commonly occurs as Crystal twinning, twinned crystal ''wikt:trilling, trillings'' (compound crystals comprising three twinned crystal components). Structure Tridymite can occur in seven crystalline forms. Two of the most common at standard pressure are known as α and β. The α-tridymite phase is favored at elevated temperatures (above 870 °C) and it converts to β-cristobalite at 1,470 °C. However, tridymite does usually not form from pure β-quartz, one needs to add trace amounts of certain compounds to achieve t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schreibersite
Schreibersite is generally a rare iron nickel phosphide mineral, , though common in iron-nickel meteorites. It has been found on Disko Island in Greenland and Illinois. Another name used for the mineral is rhabdite. It forms tetragonal crystals with perfect 001 cleavage. Its color ranges from bronze to brass yellow to silver white. It has a density of 7.5 and a hardness of 6.5 – 7. It is opaque with a metallic luster and a dark gray streak. It was named after the Austrian scientist Carl Franz Anton Ritter von Schreibers (1775–1852), who was one of the first to describe it from iron meteorites.Schreibersite Webmineral Schreibersite is reported from the Magura Meteorite, Arva-(present name – Orava), ; ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyroxene
The pyroxenes (commonly abbreviated Px) are a group of important rock-forming inosilicate minerals found in many igneous and metamorphic rocks. Pyroxenes have the general formula , where X represents ions of calcium (Ca), sodium (Na), iron (Fe(II)) or magnesium (Mg) and more rarely zinc, manganese or lithium, and Y represents ions of smaller size, such as chromium (Cr), aluminium (Al), magnesium (Mg), cobalt (Co), manganese (Mn), scandium (Sc), titanium (Ti), vanadium (V) or even iron (Fe(II) or Fe(III)). Although aluminium substitutes extensively for silicon in silicates such as feldspars and amphiboles, the substitution occurs only to a limited extent in most pyroxenes. They share a common structure consisting of single chains of silica tetrahedra. Pyroxenes that crystallize in the monoclinic system are known as clinopyroxenes and those that crystallize in the orthorhombic system are known as orthopyroxenes. The name ''pyroxene'' is derived from the Ancient Greek w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Merrillite
Merrillite is a calcium phosphate mineral with the chemical formula Ca9NaMg(PO4)7. It is an anhydrous, sodium-rich member of the merrillite ''group'' of minerals. Mineral species, sub-group and group Merrillite is a distinct ''mineral species'' but it also gives its name to a set of similar minerals, which together form the merrillite ''sub-group'' of minerals. The merrillite sub-group and the whitlockite sub-group together form the merrillite ''group'' of minerals. *Merrillite Group **Merrillite Sub-group *** Ferromerrillite *** Keplerite *** Matyhite ***Merrillite **Whitlockite Sub-group *** Hedegaardite *** Strontiowhitlockite ***Whitlockite *** Wopmayite In September 2022 the discovery of another merrillite group mineral, changesite–(Y), was announced, but, , it is not yet clear where this new mineral sits in the merrillite group hierarchy. Discovery and naming Merrillite is named after George P. Merrill (1854–1929) of the Smithsonian Institution. In 1915, M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ilmenite
Ilmenite is a titanium-iron oxide mineral with the idealized formula . It is a weakly magnetic black or steel-gray solid. Ilmenite is the most important ore of titanium and the main source of titanium dioxide, which is used in paints, printing inks, fabrics, plastics, paper, sunscreen, food and cosmetics. Structure and properties Ilmenite is a heavy (specific gravity 4.7), moderately hard (Mohs hardness 5.6 to 6), opaque black mineral with a submetallic luster. It is almost always massive, with thick tabular crystals being quite rare. It shows no discernible cleavage, breaking instead with a conchoidal to uneven fracture. Ilmenite crystallizes in the trigonal system with space group ''R''. The ilmenite crystal structure consists of an ordered derivative of the corundum structure; in corundum all cations are identical but in ilmenite Fe2+ and Ti4+ ions occupy alternating layers perpendicular to the trigonal c axis. Pure ilmenite is paramagnetic (showing only very weak ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Graphite
Graphite () is a Crystallinity, crystalline allotrope (form) of the element carbon. It consists of many stacked Layered materials, layers of graphene, typically in excess of hundreds of layers. Graphite occurs naturally and is the most stable form of carbon under standard conditions. Synthetic and natural graphite are consumed on a large scale (1.3million metric tons per year in 2022) for uses in many critical industries including refractories (50%), lithium-ion batteries (18%), foundries (10%), and lubricants (5%), among others (17%). Graphite converts to diamond under extremely high pressure and temperature. Graphite's low cost, thermal and chemical inertness and characteristic conductivity of heat and electricity finds numerous applications in high energy and high temperature processes. Types and varieties Graphite can occur naturally or be produced synthetically. Natural graphite is obtained from naturally occurring geologic deposits and synthetic graphite is produced t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Feldspar
Feldspar ( ; sometimes spelled felspar) is a group of rock-forming aluminium tectosilicate minerals, also containing other cations such as sodium, calcium, potassium, or barium. The most common members of the feldspar group are the ''plagioclase'' (sodium-calcium) feldspars and the ''alkali'' (potassium-sodium) feldspars. Feldspars make up about 60% of the Earth's crust and 41% of the Earth's continental crust by weight. Feldspars crystallize from magma as both intrusive and extrusive igneous rocks and are also present in many types of metamorphic rock. Rock formed almost entirely of calcic plagioclase feldspar is known as anorthosite. Feldspars are also found in many types of sedimentary rocks. Etymology The name ''feldspar'' derives from the German , a compound of the words ' ("field") and ("flake"). had long been used as the word for "a rock easily cleaved into flakes"; was introduced in the 18th century as a more specific term, referring perhaps to its comm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Daubréelite
Daubréelite is a rare sulfide mineral. It crystallizes with Cubic crystal system, 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 paragenesis, 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 Hoba me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cohenite
Cohenite is a naturally occurring iron carbide mineral with the chemical structure ( Fe, Ni, Co)3 C. This forms a hard, shiny, silver mineral which was named by E. Weinschenk in 1889 after the German mineralogist Emil Cohen, who first described and analysed material from the Magura meteorite found near Slanica, Žilina Region, Slovakia. Cohenite is found in rod-like crystals in iron meteorites.Vagn F. Buchwald, ''Handbook of Iron Meteorites,'' University of California Press, 1975 On Earth cohenite is stable only in rocks which formed in a strongly reducing environment and contain native iron deposits. Such conditions existed in some places where molten magmas invaded coal deposits, e.g. on Disko Island in Greenland, or at the Bühl near Kassel in Germany. Associated minerals include native iron, schreibersite, troilite and wüstite. Similar iron carbides occur also in technical iron alloys and are called cementite. See also * Edscottite * Glossary of meteoritics *List ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
