Your browser does not seem to support JavaScript. As a result, your viewing experience will be diminished, and you have been placed in read-only mode.
Please download a browser that supports JavaScript, or enable it if it's disabled (i.e. NoScript).
A basic, dark-colored, holocrystalline, igneous rock,consisting essentially of a triclinic feldspar and pyroxene withmagnetic iron; -- often limited to rocks pretertiary in age. Itincludes part of what was early called greenstone.