Definition of xenocryst in English:

xenocryst

Pronunciation /ˈzenəˌkrist/ /ˈzēnə-/ /ˈzɛnəkrɪst/

noun

Geology
  • A crystal in an igneous rock which is not derived from the original magma.

    ‘This could represent a xenocryst derived from Archaean basement rocks of the region.’
    • ‘Again, the lack of zircon xenocrysts in this sample does not allow discrimination between these alternatives.’
    • ‘The xenocrysts provide evidence that earlier Neoproterozoic rocks were present in the region and that locally rocks date back to 1929 Ma.’
    • ‘We interpret these grains as xenocrysts from an older source terrain from which the granitic protolith of sample MS 3 may have been derived by anatectic melting.’
    • ‘Xenoliths, which are pieces of wall rock, or xenocrysts, which are single mineral grains that originate from xenoliths, can commonly be recognized at outcrops of magmatic rocks.’

Origin

Late 19th century from xeno-‘foreign’ + crystal.