diabase

1 definition found

diabase - Collaborative International Dictionary of English v.0.48 :

  Diabase \Di"a*base\, n. [F. diabase, fr. Gr. ? a crossing or
     passing over, fr. ?; ? + ? to go; -- so called by Brongniart,
     because it passes over to diorite.] (Min.)
     A basic, dark-colored, holocrystalline, igneous rock,
     consisting essentially of a triclinic feldspar and pyroxene
     with magnetic iron; -- often limited to rocks pretertiary in
     age. It includes part of what was early called greenstone.
     [1913 Webster]