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

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]