Structure Allende meteorite

allende meteorite - image matteo chinellato; cube = 1 cm

the meteorite formed nebular dust , gas during formation of solar system. stony meteorite, opposed iron, or stony iron, other 2 general classes of meteorite. allende stones covered, in part or in whole, black, shiny crust created stone descended @ great speed through atmosphere falling towards earth space. causes exterior of stone become hot, melting it, , forming glassy fusion crust.

when allende stone sawed 2 pieces , surface polished, structure in interior can examined. reveals dark matrix embedded throughout mm-sized, lighter-colored chondrules, tiny stony spherules found in meteorites , not in earth rock (thus chondritic meteorite). seen white inclusions, several cm in size, ranging in shape spherical highly irregular or amoeboidal. these known calcium-aluminum-rich inclusions or cais , named because dominantly composed of calcium- , aluminum-rich silicate , oxide minerals. many chondrites, allende breccia, , contains many dark-colored clasts or dark inclusions have chondritic structure distinct rest of meteorite. unlike many other chondrites, allende lacking in fe-ni metal.