<p>Limestone is a sedimentary rock made up mainly of the mineral calcite (calcium carbonate). It may be made up of biogenic calcite such as shells or inorganic calcite deposited as fine grained "<a href="https://en.wikipedia.org/wiki/Micrite" rel="nofollow noreferrer">micrite</a>" although some micrite may also have a biological origin.</p>

<p>Animals don't have bones made from gypsum so all gypsum deposits have non-biological origin.</p>

CC BY-SA 3.0
2018-01-30T11:13:59.907Z
Where does the Calcium in Gypsum come from? Is it from the bones of marine animals?
Porcupine
CC BY-SA 3.0
2018-01-30T00:15:22.030Z
2018-01-30T00:15:22.030Z
haresfur
<p>I read that limestone is made from the compaction of marine animals' bones. But, I am unable to find out why limestone could not have been produced from <a href="https://en.wikipedia.org/wiki/Abundance_of_elements_in_Earth%27s_crust" rel="nofollow noreferrer">calcium occurring naturally (5th most abundant element in earth's crust) in the Earth Crust and in the mantle?</a></p>

<p>Is gypsum also produced from marine animal's bones?</p>

CC BY-SA 4.0
2018-06-06T14:51:36.687Z
Related: https://earthscience.stackexchange.com/questions/14354/in-an-earth-like-planet-with-no-history-of-carbon-based-life-forms-would-there and https://earthscience.stackexchange.com/questions/2295/formation-of-limestone-without-living-organisms
TylerH
<rocks><mineralogy><sedimentology>
Inorganic Limestone and Inorganic Gypsum
Porcupine
# Inorganic Limestone and Inorganic Gypsum

(Asked by: username_0 on 2018-01-29)

I read that limestone is made from the compaction of marine animals' bones. But, I am unable to find out why limestone could not have been produced from [calcium occurring naturally (5th most abundant element in earth's crust) in the Earth Crust and in the mantle?](https://en.wikipedia.org/wiki/Abundance_of_elements_in_Earth%27s_crust)

Is gypsum also produced from marine animal's bones?

**Tags:** rocks, mineralogy, sedimentology

> **Comments:**
> **username_1**: Related: https://earthscience.stackexchange.com/questions/14354/in-an-earth-like-planet-with-no-history-of-carbon-based-life-forms-would-there and https://earthscience.stackexchange.com/questions/2295/formation-of-limestone-without-living-organisms  

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## 1 answers

### Answer by username_2 on 2018-01-30. Score: 1

Limestone is a sedimentary rock made up mainly of the mineral calcite (calcium carbonate). It may be made up of biogenic calcite such as shells or inorganic calcite deposited as fine grained "[micrite](https://en.wikipedia.org/wiki/Micrite)" although some micrite may also have a biological origin.

Animals don't have bones made from gypsum so all gypsum deposits have non-biological origin.

> **Comments:**
> **username_0**: Where does the Calcium in Gypsum come from? Is it from the bones of marine animals?  

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