<p>I think you are correct. Typical sand is silica (white) with a little Fe<sub>2</sub>O<sub>3</sub> (red) to give a "sand" color. FeO is black and over geological time in air, oxidizes further to Fe<sub>3</sub>O<sub>4</sub> with hydroxides and hydrates (black and dark brown) and eventually Fe<sub>2</sub>O<sub>3</sub>. </p>

CC BY-SA 3.0
2017-08-12T22:48:34.317Z
Let me just add that "FeO" probably doesn't even exist in the top few tens of kms (or maybe even hundreds of kms) of the earth. It is common as a component in other minerals (such as fayalite olivine) but never on its own. Fe2O3 on the other hand, is a common mineral: hematite.
Gimelist
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2017-08-12T00:43:19.207Z
2017-08-12T22:50:22.797Z
2017-08-12T22:50:22.797Z
blacksmith37
<p>It is repeated often that Saharan calimas are fertilizing often Atlantic ocean. But I suppose that most of Saharan dust contains Fe<sub>2</sub>O<sub>3</sub> and not FeO. Am I right?</p>

<geochemistry><geobiology>
Saharian calima dust, apart of Fe2O3 does contain FeO?
luis blas Cabrera
# Saharian calima dust, apart of Fe2O3 does contain FeO?

(Asked by: username_0 on 2017-08-11)

It is repeated often that Saharan calimas are fertilizing often Atlantic ocean. But I suppose that most of Saharan dust contains Fe2O3 and not FeO. Am I right?

**Tags:** geochemistry, geobiology


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## 1 answers

### Answer by username_1 on 2017-08-12. Score: 3

I think you are correct. Typical sand is silica (white) with a little Fe2O3 (red) to give a "sand" color. FeO is black and over geological time in air, oxidizes further to Fe3O4 with hydroxides and hydrates (black and dark brown) and eventually Fe2O3.

> **Comments:**
> **username_2**: Let me just add that "FeO" probably doesn't even exist in the top few tens of kms (or maybe even hundreds of kms) of the earth. It is common as a component in other minerals (such as fayalite olivine) but never on its own. Fe2O3 on the other hand, is a common mineral: hematite.  

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