chondrule

from WordNet (r) 3.0 (2006)

chondrule
    n 1: small granule (of e.g. chrysolite) found in some meteoric
         rocks

from The Collaborative International Dictionary of English v.0.48

Chondrule \Chon"drule\, n. [Dim. from Gr. ? a grain (of wheat or
   spelt), cartilage.] (Min.)
   A peculiar rounded granule of some mineral, usually enstatite
   or chrysolite, found imbedded more or less abundantly in the
   mass of many meteoric stones, which are hence called
   chondrites.
   [1913 Webster]