Ordinary chondrite (North West Africa 070 Meteorite) from the Asteroid Belt between Mars and Jupiter. (cut slice; polished surface; ~13.0 centimeters across at its widest)

Chondrites are the most common type of meteorites that fall to Earth. Chondrite classification is moderately complicated, and considers isotopic, chemical, mineralogical, textural, metamorphic, and weathering factors. Chondrites are derived from bodies in the Asteroid Belt that never underwent differentiation. That is, the parent bodies never experienced a heating event sufficient to produce a core, mantle, and crust.

All chondrites contain spherical to subspherical to somewhat irregularly shaped structures called chondrules. Chondrules are composed principally of mafic minerals (olivine and pyroxene). Chondrules are nearly the oldest materials in the entire solar system. Chondrites subjected to significant thermal metamorphism some time in their history have chondrules that are partially to almost completely recrystallized.

The North West Africa (NWA) 070 Meteorite was found in 2000 in northwestern Africa's Sahara Desert. NWA 070 is an H6 ordinary chondrite. "H" means high total iron content - notice the numerous, silvery-colored, metallic iron masses in the rock (click on the photo to zoom in). "6" refers to an intensely recrystallized chondritic rock, such that almost all of the chondrules are indiscernible.

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