The following descriptions of meteorite minerals are not exhaustive, but
should give you an idea of some of the important components of meteorites.
Metallic iron minerals make up the largest percentage of iron meteorites
and stony iron meteorites. They are also important in chondrites.
-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.
--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.
-this is not a mineral, but is a mixture of fine-grained kamacite and
taenite. Scientists have distinguished several types of plessite based on
--FeS--Iron sulfide similar to the earthly mineral pyrrhotite. Troilite is
not magnetic. It is metallic with a slight bronze color and slight
greenish tint. It occurs as spherical or rounded nodules. Sometimes
troilite occurs as plates (lamellae) parallel to the cubic structure of
the cubic taenite structure of iron meteorites. With a few exceptions,
troilite is present in most iron meteorites.
--FeCr2S4--This iron chrome sulfide is found as exsolution lamellae in
troilite nodules or as particles in kamacite.
--(Fe,Ni,Co)3C--is iron carbonate it is closely related to cementite
(Fe3C), a mineral described in steel. It is brilliant silver. The crystal
form is orthorhombic. Cohenite is extremely hard and will quickly dull saw
blades. Cohenite is unstable at atmospheric temperatures and pressures and
over a long period of time will break down into kamacite and graphite.
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.
and Rhabdite --(Fe,Ni)3P--Iron-nickel phosphide. Schreibersite is
yellowish metallic, very hard--though not as hard as Cohenite--brittle,
and magnetic. The crystal form appears as oriented plates in the matrix of
kamacite and taenite. Plate shaped Rhabdites are found in hexahedrites.
--FeCrO4--This ore of chrome is common on earth and as a trace mineral in
iron meteorites. It is black, with cubic crystal form and octahedral
-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.
-C--The common mineral of pencil lead is common as nodules in Iron
meteorites and in carbonaceous chondrites. It is black and very soft.
--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.
--C--A hexagonal polymorph of diamond (diamond is cubic). Lonsdaleite is
mixed with diamond at Canyon Diablo.
--A group of mostly dark colored rock-forming minerals common on Earth and
in meteorites. Orthopyroxenes are a subcatagory that are found in
meteorites--particularly chondrites and achondrites. The following is a
list of a solid solution series that gradually decreases in magnesium and
increases iron content:
Enstatite --Mg2Si2O6--The end member--the one highest in magnesium.
It is grayish to yellowish to brown and an important rock former on
Earth. In meteorites it is a key constituent of the rare enstatite
Bronzite- -(Mg,Fe)SiO3--This member is usually brown or green and
often having a pearly luster. It has more iron than enstatite and more
magnesium than hypersthene.
Hypersthene --(Mg,Fe)SiO3--This mineral is similar to bronzite in
many ways, but having more iron, it will tend to be darker--even
Orthoferrosilite --FeSiO3--This is the other orthopyroxene end
member. It has the most iron and the least magnesium.
Clinopyroxenes , (monoclinic crystal structure) diopside
(CaMg(SiO3)2), hedenbergite (CaFeSi2O6), augite
((Ca,Na)(Mg,Fe,Al)(Si,Al)2O6) and pigeonite ((Mg,Fe,Al)(Mg,Fe)Si2O6)
are also found in meteorites particularly achondrites.
--(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.
-calcium, sodium. aluminum silicates-- (courtesy of S. Ray DeRusse with
thanks of www.bccmeteorites.com) are
found in meteorites especially with respect to Achondrites which are
generally differentiated by temperature and or pressure.
These samples contain abundant Feldspar as much as 35 percent for highly
The remainder is cristobalite, tridymite, pyroxene and reduced
metals such as iron and titanium oxides with minor accessories.
It would be much better to say 3 end member Feldspars because if
your sample contains anorthite this implies a hi Tc meaning it has to cool
at some point resulting in albite as the other end member.Na is
isomorphous with Ca and K but K is not isomorphous with Ca]. In the
solid solution series Ca will be used up first (high Tc) and any left over
Na will go into solution with K.
Therefore the entire range of Feldspars will generally be present. (Not
just two or three).
However Feldspars are rare in Iron-Nickel meteorites but very common
minerals in stony 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.