• Ultramafic

    Origin

    - + mafic

    Adjective

    ultramafic

    1. (geology) Describing igneous rocks that contain magnesium and iron and only a very small amount of silica, such as are found in the Earth’s mantle.

    Synonyms

    Full definition of ultramafic

    Noun

    ultramafic

    (plural ultramafics)
    1. A rock with such properties.
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