from The American HeritageĀ® Dictionary of the English Language, 4th Edition

  • adj. Containing or relating to a group of dark-colored minerals, composed chiefly of magnesium and iron, that occur in igneous rocks.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • adj. Describing rocks, such as silicate minerals, magmas, and volcanic and intrusive igneous rocks, which contain relatively high concentrations of magnesium and iron.
  • n. A rock with such properties.


ma(gnesium) + Latin f(errum), iron + -ic.
(American Heritage® Dictionary of the English Language, Fourth Edition)
Blend of magnesium and ferric. (Wiktionary)



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