Definition of serpentinite in US English:



  • A dark, typically greenish metamorphic rock, consisting largely of serpentine or related minerals, formed when mafic igneous rocks are altered by water.

    • ‘It has also been found in silica-poor igneous rocks, such as syenite, nepheline syenite, serpentinite, and lamprophyre.’
    • ‘Compositionally, the turbidites are mostly feldspathic litharenites with trace amounts of serpentinite, anorthosite and mafic volcanic clasts.’
    • ‘These rocks are ultramafic and include serpentinite, harzburgite, diallage, and rodingite.’
    • ‘The Selcuk nappe contains blocks of metagabbro in a matrix of serpentinite and garnet-mica schist.’
    • ‘The resulting rock, called serpentinite, has a much lower density than the original peridotite, thereby increasing the relative buoyancy of the future ophiolite - and with this its chances of obduction.’


1930s: from serpentine + -ite.