Anorthosite

1 definition found

From The Collaborative International Dictionary of English v.0.48 [gcide]:

  Anorthosite \A*nor"tho*site\, n. [F. anorthose triclinic
     feldspar (fr. Gr. 'an priv. + 'orqo`s straight) + -ite.]
     (Petrol.)
     A granular igneous rock composed almost exclusively of a
     soda-lime feldspar, usually labradorite.
     [Webster 1913 Suppl.]