|
Meteoric Iron
Meteoric iron, sometimes meteoritic iron, is a native metal and early-universe protoplanetary-disk remnant found in meteorites and made from the elements iron and nickel, mainly in the form of the mineral phases kamacite and taenite. Meteoric iron makes up the bulk of iron meteorites but is also found in other meteorites. Apart from minor amounts of telluric iron, meteoric iron is the only naturally occurring native metal of the element iron (in metallic form rather than in an ore) on the Earth's surface. Mineralogy The bulk of meteoric iron consists of taenite and kamacite. Taenite is a face-centered cubic and kamacite a body-centered cubic iron-nickel alloy. Meteoric iron can be distinguished from telluric iron by its microstructure and perhaps by its chemical composition also, since meteoritic iron contains more nickel and less carbon. Trace amounts of gallium and germanium in meteoric iron can be used to distinguish different meteorite types. The meteoric iron in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Widmanstätten Pattern
Widmanstätten patterns (), also known as Thomson structures, are figures of long Phase (matter), phases of nickel–iron, found in the octahedrite shapes of iron meteorite crystals and some pallasites. Iron meteorites are very often formed from a single crystal of iron-nickel alloy, or sometimes a number of large crystals that may be many meters in size, and often lack any discernable crystal boundary on the surface. Large crystals are extremely rare in metals, and in meteors they occur from extremely slow cooling from a molten state in the vacuum of space when the Solar System first formed. Once in the solid state, the slow cooling then allows the solid solution to Precipitation (chemistry), precipitate a separate phase that grows within the crystal lattice, which form at very specific angles that are determined by the lattice. In meteors, these interstitial defects can grow large enough to fill the entire crystal with needle or ribbon-like structures easily visible to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kamacite
Kamacite is an alloy of iron and nickel, which is found on Earth only in meteorites. According to the International Mineralogical Association (IMA) it is considered a proper nickel-rich variety of the mineral native iron. The proportion iron:nickel is between 90%:10% and 95%:5%; small quantities of other elements, such as cobalt or carbon may also be present. The mineral has a metallic luster, is gray and has no clear cleavage although its crystal structure is isometric-hexoctahedral. Its density is about 8 g/cm3 and its hardness is 4 on the Mohs scale. It is also sometimes called balkeneisen. The name was coined in 1861 and is derived from the Greek root ''καμακ-'' "kamak" or ''κάμαξ'' "kamaks", meaning vine-pole. It is a major constituent of iron meteorites (octahedrite and hexahedrite types). In the octahedrites it is found in bands interleaving with taenite forming Widmanstätten patterns. In hexahedrites, fine parallel lines called Neumann lines are ofte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bronze Age
The Bronze Age () was a historical period characterised principally by the use of bronze tools and the development of complex urban societies, as well as the adoption of writing in some areas. The Bronze Age is the middle principal period of the three-age system, following the Stone Age and preceding the Iron Age. Conceived as a global era, the Bronze Age follows the Neolithic, with a transition period between the two known as the Chalcolithic. The final decades of the Bronze Age in the Mediterranean basin are often characterised as a period of widespread societal collapse known as the Late Bronze Age collapse (), although its severity and scope are debated among scholars. An ancient civilisation is deemed to be part of the Bronze Age if it either produced bronze by smelting its own copper and alloying it with tin, arsenic, or other metals, or traded other items for bronze from producing areas elsewhere. Bronze Age cultures were the first to History of writing, develop writin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iron Age
The Iron Age () is the final epoch of the three historical Metal Ages, after the Chalcolithic and Bronze Age. It has also been considered as the final age of the three-age division starting with prehistory (before recorded history) and progressing to protohistory (before written history). In this usage, it is preceded by the Stone Age (subdivided into the Paleolithic, Mesolithic and Neolithic) and Bronze Age. These concepts originated for describing Iron Age Europe and the ancient Near East. In the archaeology of the Americas, a five-period system is conventionally used instead; indigenous cultures there did not develop an iron economy in the pre-Columbian era, though some did work copper and bronze. Indigenous metalworking arrived in Australia with European contact. Although meteoric iron has been used for millennia in many regions, the beginning of the Iron Age is defined locally around the world by archaeological convention when the production of Smelting, smelted iron (espe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Smelting
Smelting is a process of applying heat and a chemical reducing agent to an ore to extract a desired base metal product. It is a form of extractive metallurgy that is used to obtain many metals such as iron-making, iron, copper extraction, copper, silver mining#Ore processing, silver, tin, lead smelting, lead and zinc smelting, zinc. Smelting uses heat and a chemical reducing agent to decompose the ore, driving off other elements as gases or slag and leaving the metal behind. The reducing agent is commonly a fossil-fuel source of carbon, such as carbon monoxide from incomplete combustion of coke (fuel), coke—or, in earlier times, of charcoal. The oxygen in the ore binds to carbon at high temperatures, as the Chemical energy, chemical potential energy of the bonds in carbon dioxide () is lower than that of the bonds in the ore. Sulfide ores such as those commonly used to obtain copper, zinc or lead, are roasting (metallurgy), roasted before smelting in order to convert the sulfid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meteorite Iron Harpoon 2023
A meteorite is a rock that originated in outer space and has fallen to the surface of a planet or moon. When the original object enters the atmosphere, various factors such as friction, pressure, and chemical interactions with the atmospheric gases cause it to heat up and radiate energy. It then becomes a meteor and forms a fireball, also known as a shooting star; astronomers call the brightest examples " bolides". Once it settles on the larger body's surface, the meteor becomes a meteorite. Meteorites vary greatly in size. For geologists, a bolide is a meteorite large enough to create an impact crater. Meteorites that are recovered after being observed as they transit the atmosphere and impact Earth are called meteorite falls. All others are known as meteorite finds. Meteorites have traditionally been divided into three broad categories: stony meteorites that are rocks, mainly composed of silicate minerals; iron meteorites that are largely composed of ferronickel; and stony ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neumann Lines
Neumann lines, or Neumann bands, are fine patterns of parallel lines seen in cross-sections of many hexahedrite iron meteorites in the kamacite phase, although they may appear also in octahedrites provided the kamacite phase is about 30 micrometres wide. They can be seen after a polished meteorite cross-section is treated with acid. The lines are indicative of a shock-induced deformation of the kamacite crystal, and are thought to be due to impact events on the parent body of the meteorite. Neumann lines are named after who discovered them in 1848 in the hexahedrite meteorite which had fallen near Braunau (present-day Broumov, Czech Republic) in 1847.J. G. Burke: Cosmic Debris, Meteorites in History. University of California Press, 1986. See also * Glossary of meteoritics *Widmanstätten pattern Widmanstätten patterns (), also known as Thomson structures, are figures of long Phase (matter), phases of nickel–iron, found in the octahedrite shapes of iron meteorite ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plessite
Plessite is a meteorite texture consisting of a fine-grained mixture of the minerals kamacite and taenite found in the octahedrite iron meteorites. It occurs in gaps (its name is derived from the Greek "plythos" meaning "filling"according tMindat a mineral database and mineralogical reference website) between the larger bands of kamacite and taenite which form Widmanstätten patterns. Many types of plessite exist and vary in formation mechanism and morphology. Some types of plessite as named by Buchwald's "Iron Meteorites" and Massalski's "Speculations about Plessite" are: *acicular or type I plessite *black or type II plessite *cellular or type III plessite *comb plessite *net plessite *pearlitic plessite *spheroidized plessite 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-larges ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exsolution
A solid solution, a term popularly used for metals, is a homogeneous mixture of two compounds in solid state and having 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 the brand na ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thin Section
In optical mineralogy and petrography, a thin section (or petrographic thin section) is a thin slice of a rock or mineral sample, prepared in a laboratory, for use with a polarizing petrographic microscope, electron microscope and electron microprobe. A thin sliver of rock is cut from the sample with a diamond saw and ground optically flat. It is then mounted on a glass slide and then ground smooth using progressively finer abrasive grit until the sample is only 30 μm thick. The method uses the Michel-Lévy interference colour chart to determine thickness, typically using quartz as the thickness gauge because it is one of the most abundant minerals. When placed between two polarizing filters set at right angles to each other, the optical properties of the minerals in the thin section alter the colour and intensity of the light as seen by the viewer. As different minerals have different optical properties, most rock forming minerals can be easily identified. Plagioclase ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Etching
Etching is traditionally the process of using strong acid or mordant to cut into the unprotected parts of a metal surface to create a design in intaglio (incised) in the metal. In modern manufacturing, other chemicals may be used on other types of material. As a method of printmaking, it is, along with engraving, the most important technique for old master prints, and remains in wide use today. In a number of modern variants such as microfabrication etching and photochemical milling, it is a crucial technique in modern technology, including circuit boards. In traditional pure etching, a metal plate (usually of copper, zinc or steel) is covered with a waxy ground which is resistant to acid. The artist then scratches off the ground with a pointed etching needle where the artist wants a line to appear in the finished piece, exposing the bare metal. The échoppe, a tool with a slanted oval section, is also used for "swelling" lines. The plate is then dipped in a bath of aci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetrataenite
Tetrataenite is a native metal alloy composed of chemically-ordered L10-type , recognized as a mineral in 1980. The mineral is named after its tetragonal crystal structure and its relation to the iron-nickel alloy, taenite, which is chemically disordered (A1) phase with an underlying fcc lattice. Tetrataenite is one of the mineral phases found in meteoric iron. Before its discovery in meteoritic samples, experimental synthesis of the L10 phase was first reported in 1962 by Louis Néel and co-workers, following neutron irradiation of a chemically disordered FeNi sample under an applied magnetic field. Compared to the magnetically soft, chemically disordered A1 phase (taenite), the tetragonal L10 structure of tetrataenite leads to good hard magnetic properties, including a large uniaxial magnetocrystalline anisotropy energy. Consequently, it is under consideration for applications as a rare-earth-free permanent magnet. Formation Tetrataenite forms naturally in iron meteorites that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
