Here's why:
* Ferromagnesian minerals are dark-colored minerals rich in iron (Fe) and magnesium (Mg). Examples include olivine, pyroxene, and amphibole.
* Mafic rocks are igneous rocks that are relatively high in magnesium and iron. They are typically dark in color due to the presence of ferromagnesian minerals.
Some common examples of mafic rocks include:
* Basalt: A fine-grained, volcanic rock.
* Gabbro: A coarse-grained, intrusive rock.
Note: While mafic rocks are primarily composed of ferromagnesian minerals, they can also contain other minerals like plagioclase feldspar.
