<p>Soapstone is a form of talc. It is basically talc plus other minerals, such as micas, chlorite and amphiboles, depending on the initial rocks that were metamorphosed. Soapstone is also called a <a href="https://geologyscience.com/rocks/soapstone/" rel="nofollow noreferrer">talc-schist</a>.</p>
<p><a href="https://en.wikipedia.org/wiki/Soapstone" rel="nofollow noreferrer">Soapstone</a> is formed by the <a href="https://en.wikipedia.org/wiki/Metamorphism" rel="nofollow noreferrer">metamorphism</a> of <a href="https://en.wikipedia.org/wiki/Ultramafic_rock" rel="nofollow noreferrer">ultramafic</a> protoliths, such as <a href="https://en.wikipedia.org/wiki/Dunite" rel="nofollow noreferrer">dunite</a> or <a href="https://en.wikipedia.org/wiki/Serpentinite" rel="nofollow noreferrer">serpentinite</a> and the <a href="https://en.wikipedia.org/wiki/Metasomatism" rel="nofollow noreferrer">metasomatism</a> of siliceous <a href="https://en.wikipedia.org/wiki/Dolomite_(rock)" rel="nofollow noreferrer">dolomites</a>. The metamorphism occurs in the regions where tectonic plates are present, where the rocks are subjected to heat and pressure, with flowing liquids, but without melting. <a href="https://www.thoughtco.com/metamorphic-rock-types-4122981" rel="nofollow noreferrer">Soapstone</a> is derived from <a href="https://geologyscience.com/applied-geology/mining-geology/hydrothermal-alteration/" rel="nofollow noreferrer">hydrothemal alteration</a> of <a href="https://en.wikipedia.org/wiki/Peridotite" rel="nofollow noreferrer">peridotite</a> and related ultramafic rocks.</p>

CC BY-SA 4.0
2020-11-13T00:47:57.647Z
2020-11-13T00:47:57.647Z
Fred
<blockquote>
<p>My understanding is that soapstone is talc (hydrated magnesium silicate) which has been metamorphically transformed</p>
</blockquote>
<p>Not quite. Soapstone is talc-rich rock. The way you put, you had talc to begin with, then it was metamorphosed, and something happened to the talc to transform it into soapstone. This is not accurate.</p>
<p>You had something else to begin with (see Fred's answer), and it was transformed into talc-containing soapstone during metamorphism.</p>

CC BY-SA 4.0
2020-11-16T09:41:01.610Z
2020-11-16T09:41:01.610Z
Gimelist
<p>My understanding is that soapstone is talc (hydrated magnesium silicate) which has been metamorphically transformed. However, it is not clear to me how this transformation affects the talc.</p>
<p>What is the difference between talc and soapstone?</p>

<mineralogy>
How does metamorphism change talc into soapstone?
Tyler Durden
# How does metamorphism change talc into soapstone?

(Asked by: username_0 on 2020-11-08)

My understanding is that soapstone is talc (hydrated magnesium silicate) which has been metamorphically transformed. However, it is not clear to me how this transformation affects the talc.

What is the difference between talc and soapstone?

**Tags:** mineralogy


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## 2 answers

### Answer by username_1 on 2020-11-13. Score: 4

Soapstone is a form of talc. It is basically talc plus other minerals, such as micas, chlorite and amphiboles, depending on the initial rocks that were metamorphosed. Soapstone is also called a [talc-schist](https://geologyscience.com/rocks/soapstone/).

[Soapstone](https://en.wikipedia.org/wiki/Soapstone) is formed by the [metamorphism](https://en.wikipedia.org/wiki/Metamorphism) of [ultramafic](https://en.wikipedia.org/wiki/Ultramafic_rock) protoliths, such as [dunite](https://en.wikipedia.org/wiki/Dunite) or [serpentinite](https://en.wikipedia.org/wiki/Serpentinite) and the [metasomatism](https://en.wikipedia.org/wiki/Metasomatism) of siliceous [dolomites](https://en.wikipedia.org/wiki/Dolomite_(rock)). The metamorphism occurs in the regions where tectonic plates are present, where the rocks are subjected to heat and pressure, with flowing liquids, but without melting. [Soapstone](https://www.thoughtco.com/metamorphic-rock-types-4122981) is derived from [hydrothemal alteration](https://geologyscience.com/applied-geology/mining-geology/hydrothermal-alteration/) of [peridotite](https://en.wikipedia.org/wiki/Peridotite) and related ultramafic rocks.


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### Answer by username_2 on 2020-11-16. Score: 2

> My understanding is that soapstone is talc (hydrated magnesium silicate) which has been metamorphically transformed

Not quite. Soapstone is talc-rich rock. The way you put, you had talc to begin with, then it was metamorphosed, and something happened to the talc to transform it into soapstone. This is not accurate.

You had something else to begin with (see username_1's answer), and it was transformed into talc-containing soapstone during metamorphism.


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