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April 18, 2017

While not a Ferris wheel, this EarthWord is just as magnetic an attraction...

EarthWords is an on-going series in which we shed some light on the complicated, often difficult-to-pronounce language of science. Think of us as your terminology tour-guides, and meet us back here every week for a new word!

A piece of limonite, an ore of iron.
A piece of limonite, an ore of iron. Credit: Alex Demas, USGS.(Public domain.)

The EarthWord: Ferrous


  • Sadly this is not the same as a Ferris wheel. This ferrous refers to the presence of iron in a mineral. A ferrous mineral has iron, a non-ferrous one does not.


  • Ferrous comes to us from the Latin ferrum, which means “iron.” That’s also where the Atomic symbol for iron, Fe, comes from.

Use/Significance in the Earth Science Community:

  • The study of ferrous minerals is important for a couple of reasons. The first is that iron and its related metals are very important to the world’s economy. In fact, iron and steel comprise about 95 percent of all the tonnage of metal produced annually in the United States and the world.

  • Another main reason why studying ferrous minerals is important is that many useful mineral occur alongside the ferrous ones. That means that when you mine the iron, you can also get the other minerals, a process known as co-production. In many cases, that’s how minerals that would not be worth enough to mine on their own can be produced profitably.

  • Finally, ferrous minerals can have different environmental effects when mined. The ferrous mineral pyrite can create acid mine drainage when exposed to oxygen and water. Acid mine drainage can have a number of negative environmental effects.


Next EarthWord: Whether you pan for gold or rare earths, you’ll get a lot of sand...and this EarthWord!

Hungry for some science, but you don’t have time for a full-course research plate? Then check out USGS Science Snippets, our snack-sized science series that focuses on the fun, weird, and fascinating stories of USGS science.

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