mafic

/ˈmæfɪk/
adjective
  1. Describing a type of igneous rock that is rich in magnesium and iron, and is usually dark in color.
    • Basalt is a common mafic rock found on the ocean floor.
    • Mafic minerals like olivine and pyroxene give the rock its greenish-black color.
    • The geologist identified the dark, heavy sample as mafic in composition.
Antonyms