Mafic

The term mafic is a portmanteau of "magnesium" and "ferric" and was coined by Charles Whitman Cross, Joseph P. Iddings, Louis V. Pirsson, and Henry Stephens Washington in 1912.

[1] Cross and his coinvestigators later clarified that micas and aluminium amphiboles belonged to a separate category of alferric minerals.

[3] Modern classification schemes, such as the International Union of Geological Sciences (IUGS) classification of igneous rocks, include some light-colored ferromagnesian minerals, such as melilite, in the mafic mineral fraction.

[8] Such rocks are enriched in iron, magnesium and calcium and typically dark in color.

In contrast, the felsic rocks are typically light in color and enriched in aluminium and silicon along with potassium and sodium.