Meteorite Minerals
Meteorite Minerals
The following descriptions of meteorite minerals are not exhaustive, but should give you an idea of some of the important components of meteorites. You can look through this list or access this page through the links from other pages. When everything is complete, clicking on a mineral name will bring you to this page.
Kamacite--this is essentially metallic iron with up to 7.5% nickel in solid solution. In cut sections kamacite looks like metallic iron and like the other important nickel-iron mineral, taenite. On etched and polished surfaces, sometimes it can be distinguished. Kamacite may have Neumann bands--lines that are created when meteorites are shocked. Kamacite occurs as rims around troilite or schreibersite--swathing kamacite. Sometimes on polished surfaces, kamacite may be distinguished from taenite because it is not as hard.
Taenite--this is iron with more than 25 percent nickel in solid solution. The atoms of taenite arrange themselves in a cube form with an atom centered in the face. In non-meteoritic metals this mineral is called austenite. Taenite is resistant to the nitol etching process, thus the plates of taenite stand out after the etching process. Polishing sometimes allows one to distinguish taenite. Because it is harder it stands out.
Plessite--this is not a mineral, but is a mixture of fine-grained kamacite and taenite. Scientists have distinguished several types of plessite based on microscopic structures.
Daubreelite--FeCr2S4--This iron chrome sulfide is found as exsolution lamellae in troilite nodules or as particles in kamacite.
Haxonite--(Fe,Ni,Co)23C6--is a cubic iron carbide similar to minerals found in steel. It to is hard, though not as hard as Cohenite. It is bright silver. Like Cohenite, it is unstable at atmospheric temperatures and pressures and will gradually decompose to kamacite and graphite.
Magnetite--Fe3O4--A common ore of iron on earth is found in the crusts of most meteorites and in carbonaceous chondrites. Magnetite is submetallic black with cubic crystal form and octahedral cleavage.
corundum--Al2O3--This mineral is what rubies and sapphires are made of--it is also a trace mineral in meteorites. Dont look for red or blue. Gray is the probable color.
Diamond--C--This is the same element as graphite. When graphite is subjected to the extraordinarily high temperature and pressure of meteorite impact, sometimes diamonds will form. Canyon Diablo meteorites have some.
Lonsdaleite--C--A hexagonal polymorph of diamond (diamond is cubic). Lonsdaleite is mixed with diamond at Canyon Diablo.
Olivine--(Mg,Fe)2SiO4--is a rock forming mineral on Earth that is believed to have been formed at great depth. The Earth's mantle may have significant olivine. In meteorites, olivine is important in some pallasites. The olivines are a solid solution series with forsterite containing the most magnesium and fayalite having the most iron. The olivine in most stony iron meteorites ranges in composition from 60 to 85 percent forsterite with the remainder being fayalite.
Feldspars--calcium, sodium. aluminum silicates--are the most important rock forming minerals in the crust of the Earth, but are relatively scarce in meteorites. There are two main groups of feldspars, plagioclase and orhtoclase. Each group is broken down into several intermediate members depending on the calcium and sodium content. Plagioclase is more common and noted varieties include albite, oligoclase, labradorite, bytownite, and anorthite.
Phylosilicates or clays are found in some meteorites.
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