Differentiated meteorites

Those meteorites come from "differentiated parent bodies".
Some come from the surface of such parent bodies and some other ones from the inside, and are very different from each other:


Polished section of a "Diogenite" (one of the achondrite types)

Those "chondrule less" and "iron less" meteorites come from the surface of differentiated bodies. They represent approxiately 7% of the falls. Those "space rocks" ressemble very much terrestrial basalts, which makes it very difficult to identify them on the field. In this case, only the presence of fusion crust proving that it travelled through the atmosphere shows that we found a meteorite.


They are classified according to their calcium content:

-Achondrites rich in CaO: Angrites,Eucrites,Howardite,...

-Achondrites poor in CaO: Diogenites,Ureilites,Aubrites,..



Those meteorites come from the core of differentiated parent bodies. They are nearly exclusively made of iron and nickel, plus some few minerals. When etching a polished surface of such a meteorite with acid, its specific crystallisation orientation appears, called "Widmanstatten patterns":

This specific structure only exists in extra-terrestrial bodies and correspond to an extremely slow cooling process of the heated parent body.


Mixt meteorites


Those gorgeous meteorites are made of an iron-nickel matrix and crystallised olivine grains. They probably come from the limit betwwen the core and the rock mantel of a differentiated parent body.


They are made of a metalic matrix and included achondrite fragments. Scientists believe that they were produced by a collisions between "iron" parent bodies and stony differentiated ones.

Non Differentiated Meteorites 

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