Search results
Results from the WOW.Com Content Network
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-iron meteorites that contain large amounts of both metallic and rocky material.
A meteorite mineral is a mineral found chiefly or exclusively within meteorites or meteorite-derived material. [citation needed] This is a list of those minerals, excluding minerals also commonly found in terrestrial rocks. As of 1997 there were approximately 295 mineral species which have been identified in meteorites. [1]
Meteoric iron, sometimes meteoritic iron, [1] 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
Iron meteorites, also called siderites or ferrous meteorites, are a type of meteorite that consist overwhelmingly of an iron–nickel alloy known as meteoric iron that usually consists of two mineral phases: kamacite and taenite. Most iron meteorites originate from cores of planetesimals, [3] with the exception of the IIE iron meteorite group. [4]
Fossil meteorite – a meteorite that was buried under layers of sediment before the start of the Quaternary period. Some or all of the original cosmic material has been replaced by diagenetic minerals. [3]: 320 (It is, however, not a fossil). Fusion crust – a coating on meteorites that forms during their passage through the atmosphere.
They are composed mainly of silicates, oxides and sulfides, with the minerals olivine and serpentine being characteristic. The presence of volatile organic chemicals and water indicates that they have not undergone significant heating (>200 °C) since they were formed, and their compositions are considered to be close to that of the solar ...
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.
Concentrations of trace elements (germanium, gallium and iridium) are used to separate the iron meteorites into chemical classes, which correspond to separate asteroid parent bodies. Chemical classes that include hexahedrites are: [4] IIAB meteorites (includes also some octahedrites) IIG meteorites