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mafic vs. felsic

mafic vs. felsic: What's the difference?

Mafic and felsic are descriptive terms used in the classification of igneous rocks (those formed from molten materials, such as lava). Mafic rocks, such as basalt, are those that are high in dark-colored minerals composed mainly of magnesium and iron. Felsic rocks, such as granite, are high in light-colored minerals, including feldspar and quartz.

[ maf-ik ]
  1. of or relating to rocks rich in dark, ferromagnesian minerals.
[ fel-sik ]
  1. (of rocks) consisting chiefly of feldspars, feldspathoids, quartz, and other light-colored minerals.

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