Fe-Mg spinelMg-Al oxide, MgAl2O4, found in CAIs., (Fe,Mg)Al2O4, found in many meteoriteWork in progress. A solid natural object reaching a planet’s surface from interplanetary space. Solid portion of a meteoroid that survives its fall to Earth, or some other body. Meteorites are classified as stony meteorites, iron meteorites, and stony-iron meteorites. These groups are further divided according to their mineralogy and classes.