<p>Soil color is largely determined by it's composition.</p>

<p>There are three main components in soil:</p>

<ul>
<li>Gravel, sand, and silt.  In essence, the type of stuff you find in sedimentary rocks. Usually, this is mostly silicate minerals like quartz, feldspar, and mica, and is usually pretty bland in terms of color.  In theory, certain silt minerals (olivines for example) can produce greenish soils, though concentrations that high are generally uncommon.  With sand involved, you can get lots of other colors (yellow, pink, purple, and even green), though this is usually only seen on beaches.</li>
<li>Clay.  Clay's often account for a large percentage of the weight of soil.  They also usually account for many of the color variations.  Most likely, that red soil near where you live has a lot of hematite rich clay in it.  Clay's mostly contribute red, yellow, and brown shades to soil, but can in theory give almost any color.  Brightly colored soils are usually the result of a sesquioxide clay, and can in theory be almost any color (red from iron, blue from copper or cobalt, green from copper, nickel, or chromium, yellow from chromium or iron, purple from manganese, etc), though only iron is particularly common.</li>
<li>Humus.  Humus is heavily decomposed organic matter.  It has a rather distinctly dark brown (almost black) color to it, and also accounts for.much of the earthy smell of soil.</li>
</ul>

<p>Beyond those, there are a few other things that may be in soil and impact the color:</p>

<ul>
<li>Charcoal. Usually found only in certain climates (warm with lots of humidity, like tropical rainforests), gives a very dark color to the soil.</li>
<li>Fungus.  There's <em>a lot</em> of fungus in soil.  Usually, it's not concentrated enough (or colorful enough) to have an impact, but in places where there is a very high concentration, it can have a localized impact on soil color.</li>
<li>Shells.  Either from diatoms (that's what diatomaceous earth is, lots and lots of microscopic shells), or very finely ground shells from bigger organisms.  You've probably seen pictures of pink or salmon colored beaches, the same effect can also happen to a much lesser degree in soil too.  Usually though, lots of shells just turns soil white.</li>
</ul>

<p>So, what color would that translate to on average?  Well, for topsoil, due to the generally high humus content, probably a rather dark brown.  Averaging over all soil, most likely something significantly lighter, as deeper soil tends to have much lower concentrations of organic matter, but likely still tan or beige.</p>

CC BY-SA 4.0
2018-06-26T12:36:16.517Z
I would also add iron to the list of things that impact colour; Given how common it is on this planet I suspect it may be responsible for more redness than clay; nice answer though
UKMonkey
CC BY-SA 4.0
2018-06-26T15:31:06.143Z
@UKMonkey Finely divided hematite (the mineral form of red rust) is almost always the culprit for making soil red.  If it's very very dry (like, Mars levels of dry), it's technically silt, though that's a rare occurrence most places here on Earth.  If it's moist as is the case in most locations on Earth, it ends up in a colloidal suspension, and is actually classified as a type of clay (part of what are known as sesquioxide clays).
Austin Hemmelgarn
CC BY-SA 4.0
2018-06-26T01:33:28.347Z
2018-06-26T20:40:48.497Z
2018-06-26T20:40:48.497Z
Austin Hemmelgarn
<p>@Muze “What would the color be if all of the dirt on Earth was added equally to a palette?” The average color of dirt is Pantone Warm Grey #11C.<img src="https://i.sstatic.net/oNeox.jpg" alt="enter image description here" /></p>

CC BY-SA 4.0
2021-12-04T04:25:54.533Z
How was this average arrived at, and by whom?
r_alex_hall
CC BY-SA 4.0
2020-10-21T15:11:03.590Z
2020-10-21T15:29:09.363Z
2020-10-21T15:29:09.363Z
Novee
<p>Where I live the soil is red.</p>

<p>Is there a map or chart where you can see the average color of the dirt according to geographical location?  What would the color be if all of the dirt on Earth was added equally to a pallet?</p>

<p>I understand that composition of minerals determines dirt color but what makes dirt its color is not the question I am asking.</p>

<p>Kata Tjuta, Northern Territory, Australia</p>

<p><a href="https://i.sstatic.net/qEQh9.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/qEQh9.jpg" alt="enter image description here"></a></p>

<p>Sagada, Mountain Province, Philippines</p>

<p><a href="https://i.sstatic.net/qbciQ.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/qbciQ.jpg" alt="enter image description here"></a></p>

<p><a href="https://eugeneexplorer.wordpress.com/2016/11/22/blue-soil-hills/" rel="nofollow noreferrer">https://eugeneexplorer.wordpress.com/2016/11/22/blue-soil-hills/</a></p>

<p>Gentry County, Missouri, United States</p>

<p><a href="https://i.sstatic.net/xPzeV.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/xPzeV.jpg" alt="enter image description here"></a></p>

<p><a href="http://www.airphotona.com/image.asp?imageid=11944" rel="nofollow noreferrer">http://www.airphotona.com/image.asp?imageid=11944</a></p>

CC BY-SA 4.0
2018-06-26T01:16:13.430Z
You know the second photo is just exposed rock, right?
lly
CC BY-SA 4.0
2018-06-26T05:05:26.213Z
'I understand that composition of minerals determines dirt color but what makes dirt its color is not the question I am asking'... Uh, **yes, it is**. Color varies according to composition, so the composition determines color. @Wanderweeer even gave you a map and you complained that it didn't have enough hues; he's giving you average values at various depths because that's what you have to do since soil color can vary over the span of a few feet... depending on its composition.
lly
CC BY-SA 4.0
2018-06-26T06:25:31.873Z
Those are heavily oversaturated photos BTW. Don't you have better ('real') ones to illustrate the question?
Jan Doggen
CC BY-SA 4.0
2018-06-26T09:57:36.973Z
@JanDoggen I can't speak to #2 or #3, but the colours in #1 are not oversaturated
Mick
CC BY-SA 4.0
2018-06-26T17:19:15.143Z
The Gentry County photo appears to be a field with colorful flowers, not the color of the soil.
David K
CC BY-SA 4.0
2018-06-26T19:22:09.243Z
@Muze Given that when I google "purple dirt missouri" the *only* reference I can find to purple dirt is that particular photo, I'd argue that either the coloring is artificial (due to fertilizers or pesticides or something), or the photographer didn't realize there were flowers down there, or it's simply a trick of the light. In any case, I don't think that's the *actual* color of the soil.
David K
CC BY-SA 4.0
2018-06-26T19:26:23.627Z
Look everybody I did research the pictures and they are legit.
Muze
CC BY-SA 4.0
2018-06-26T20:32:05.753Z
The first picture is definitely legit, though it looks like someone did bump up the saturation a bit.  The second is also legit (there actually are high copper concentrations in the soil in that area), though it looks very much like the saturation is _way_ high there.  The third is possible (manganese sesquioxide clays, or high concentrations of amethyst sand/silt), but questionable because of the fact that that's the only reference for that area.
Austin Hemmelgarn
CC BY-SA 4.0
2018-06-26T21:39:18.987Z
@AustinHemmelgarn how do you prove saturation?
Muze
CC BY-SA 4.0
2018-06-26T23:11:29.280Z
@Muze You don't.  I'm basing my statements on personal experience doing multimedia work and working in the printing industry for multiple years.  In the first case, it could also be _really_ warm lighting combined with high contrast.  The second picture though shows almost unnaturally vibrant colors though, and lherefore looks to me like it's gone through some kind of processing (could also be a high contrast filter, but the shadows don't look like they have enhanced contrast to me, so saturation makes the most sense).
Austin Hemmelgarn
<geology><soil><mapping><regional-geology>
What is the average color of soil?
Muze
# What is the average color of soil?

(Asked by: username_0 on 2018-06-25)

Where I live the soil is red.

Is there a map or chart where you can see the average color of the dirt according to geographical location? What would the color be if all of the dirt on Earth was added equally to a pallet?

I understand that composition of minerals determines dirt color but what makes dirt its color is not the question I am asking.

Kata Tjuta, Northern Territory, Australia

[![enter image description here](https://i.sstatic.net/qEQh9.jpg)](https://i.sstatic.net/qEQh9.jpg)

Sagada, Mountain Province, Philippines

[![enter image description here](https://i.sstatic.net/qbciQ.jpg)](https://i.sstatic.net/qbciQ.jpg)

<https://eugeneexplorer.wordpress.com/2016/11/22/blue-soil-hills/>

Gentry County, Missouri, United States

[![enter image description here](https://i.sstatic.net/xPzeV.jpg)](https://i.sstatic.net/xPzeV.jpg)

<http://www.airphotona.com/image.asp?imageid=11944>

**Tags:** geology, soil, mapping, regional-geology

> **Comments:**
> **username_1**: You know the second photo is just exposed rock, right?  
> **username_1**: 'I understand that composition of minerals determines dirt color but what makes dirt its color is not the question I am asking'... Uh, **yes, it is**. Color varies according to composition, so the composition determines color. @Wanderweeer even gave you a map and you complained that it didn't have enough hues; he's giving you average values at various depths because that's what you have to do since soil color can vary over the span of a few feet... depending on its composition.  
> **username_2**: Those are heavily oversaturated photos BTW. Don't you have better ('real') ones to illustrate the question?  
> **username_3**: @username_2 I can't speak to #2 or #3, but the colours in #1 are not oversaturated  
> **username_4**: The Gentry County photo appears to be a field with colorful flowers, not the color of the soil.  
> **username_4**: @username_0 Given that when I google "purple dirt missouri" the *only* reference I can find to purple dirt is that particular photo, I'd argue that either the coloring is artificial (due to fertilizers or pesticides or something), or the photographer didn't realize there were flowers down there, or it's simply a trick of the light. In any case, I don't think that's the *actual* color of the soil.  
> **username_0**: Look everybody I did research the pictures and they are legit.  
> **username_5**: The first picture is definitely legit, though it looks like someone did bump up the saturation a bit.  The second is also legit (there actually are high copper concentrations in the soil in that area), though it looks very much like the saturation is _way_ high there.  The third is possible (manganese sesquioxide clays, or high concentrations of amethyst sand/silt), but questionable because of the fact that that's the only reference for that area.  
> **username_0**: @username_5 how do you prove saturation?  
> **username_5**: @username_0 You don't.  I'm basing my statements on personal experience doing multimedia work and working in the printing industry for multiple years.  In the first case, it could also be _really_ warm lighting combined with high contrast.  The second picture though shows almost unnaturally vibrant colors though, and lherefore looks to me like it's gone through some kind of processing (could also be a high contrast filter, but the shadows don't look like they have enhanced contrast to me, so saturation makes the most sense).  

---

## 2 answers

### Answer by username_5 on 2018-06-26. Score: 8

Soil color is largely determined by it's composition.

There are three main components in soil:

* Gravel, sand, and silt. In essence, the type of stuff you find in sedimentary rocks. Usually, this is mostly silicate minerals like quartz, feldspar, and mica, and is usually pretty bland in terms of color. In theory, certain silt minerals (olivines for example) can produce greenish soils, though concentrations that high are generally uncommon. With sand involved, you can get lots of other colors (yellow, pink, purple, and even green), though this is usually only seen on beaches.
* Clay. Clay's often account for a large percentage of the weight of soil. They also usually account for many of the color variations. Most likely, that red soil near where you live has a lot of hematite rich clay in it. Clay's mostly contribute red, yellow, and brown shades to soil, but can in theory give almost any color. Brightly colored soils are usually the result of a sesquioxide clay, and can in theory be almost any color (red from iron, blue from copper or cobalt, green from copper, nickel, or chromium, yellow from chromium or iron, purple from manganese, etc), though only iron is particularly common.
* Humus. Humus is heavily decomposed organic matter. It has a rather distinctly dark brown (almost black) color to it, and also accounts for.much of the earthy smell of soil.

Beyond those, there are a few other things that may be in soil and impact the color:

* Charcoal. Usually found only in certain climates (warm with lots of humidity, like tropical rainforests), gives a very dark color to the soil.
* Fungus. There's *a lot* of fungus in soil. Usually, it's not concentrated enough (or colorful enough) to have an impact, but in places where there is a very high concentration, it can have a localized impact on soil color.
* Shells. Either from diatoms (that's what diatomaceous earth is, lots and lots of microscopic shells), or very finely ground shells from bigger organisms. You've probably seen pictures of pink or salmon colored beaches, the same effect can also happen to a much lesser degree in soil too. Usually though, lots of shells just turns soil white.

So, what color would that translate to on average? Well, for topsoil, due to the generally high humus content, probably a rather dark brown. Averaging over all soil, most likely something significantly lighter, as deeper soil tends to have much lower concentrations of organic matter, but likely still tan or beige.

> **Comments:**
> **username_6**: I would also add iron to the list of things that impact colour; Given how common it is on this planet I suspect it may be responsible for more redness than clay; nice answer though  
> **username_5**: @username_6 Finely divided hematite (the mineral form of red rust) is almost always the culprit for making soil red.  If it's very very dry (like, Mars levels of dry), it's technically silt, though that's a rare occurrence most places here on Earth.  If it's moist as is the case in most locations on Earth, it ends up in a colloidal suspension, and is actually classified as a type of clay (part of what are known as sesquioxide clays).  

---

### Answer by username_7 on 2020-10-21. Score: 2

@username_0 “What would the color be if all of the dirt on Earth was added equally to a palette?” The average color of dirt is Pantone Warm Grey #11C.![enter image description here](https://i.sstatic.net/oNeox.jpg)

> **Comments:**
> **username_8**: How was this average arrived at, and by whom?  

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