<p>Yes, there is a difference.</p>

<p>A mineral <strong>series</strong> represents mineral which have a well defined solid solution. One of the most known examples is olivine: olivine is not a strictly defined chemical composition for a mineral, but rather a series between the forsterite end-member (Mg<sub>2</sub>SiO<sub>4</sub>) and fayalite end-member (Fe<sub>2</sub>SiO<sub>4</sub>). Note that if you find a pure end-member in nature, then you have a mineral <strong>species</strong>. Quite rare for olivine though. There's also the olivine <strong>group</strong>, which consists of other minerals that do not form a solid solution with the forsterite-fayalite series (for example monticellite CaMgSiO<sub>4</sub>) or minerals that do form a solid solution, except that it's extremely rare in nature (for example tephroite Mn<sub>2</sub>SiO<sub>4</sub>). Here's a comprehensive list of the minerals in the olivine group: <a href="http://www.mindat.org/min-29264.html" rel="nofollow">http://www.mindat.org/min-29264.html</a></p>

<p>Another example is the pyroxene <strong>group</strong>. So for simple Ca-Mg-Fe pyroxenes, you have the clinopyroxene and orthopyroxene <strong>series</strong>, which consist of the end-members (<strong>species</strong>, if you find them pure) diopside (CaMgSiO<sub>6</sub>) - hedenbergite (CaFeSiO<sub>6</sub>) and enstatite (MgSiO<sub>3</sub>) - ferrosilite (FeSiO<sub>3</sub>), respectively. Intermediate clinopyroxenes are also called augite.</p>

<p>The distinction is not always clear. For example, the feldspar <strong>group</strong> traditionally has the plagioclase <strong>series</strong> (albite-anorthite, NaAlSi<sub>3</sub>O<sub>8</sub>-CaAl<sub>2</sub>Si<sub>2</sub>O<sub>8</sub>) and the K-feldspar <strong>species</strong> (KAlSi<sub>3</sub>O<sub>8</sub>, either microcline, orthoclase or sanidine, depending on structure). But in some cases there is a solid solution between albite and K-feldspar, forming the alkali-feldspar <strong>series</strong>. Nature doesn't always behave according to our rules, and it's important to remember that our classification systems work well with ideal systems but break down often.</p>

<p><a href="http://courses.missouristate.edu/emantei/mineralogy/mineral%20classif.html" rel="nofollow">Further reading</a></p>

CC BY-SA 3.0
2016-06-04T10:50:58.460Z
2016-06-04T10:50:58.460Z
Gimelist
<p>It seems to me when reading about minerals, groups and series are spoken about interchangably in similar types of contexts. Is there a difference? If so, what?</p>

<geology><geochemistry><mineralogy>
What is the difference between mineral groups and series?
D. Ataro
# What is the difference between mineral groups and series?

(Asked by: username_0 on 2016-06-04)

It seems to me when reading about minerals, groups and series are spoken about interchangably in similar types of contexts. Is there a difference? If so, what?

**Tags:** geology, geochemistry, mineralogy


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## 1 answers

### Answer by username_1 on 2016-06-04. Score: 3 | Accepted answer

Yes, there is a difference.

A mineral **series** represents mineral which have a well defined solid solution. One of the most known examples is olivine: olivine is not a strictly defined chemical composition for a mineral, but rather a series between the forsterite end-member (Mg2SiO4) and fayalite end-member (Fe2SiO4). Note that if you find a pure end-member in nature, then you have a mineral **species**. Quite rare for olivine though. There's also the olivine **group**, which consists of other minerals that do not form a solid solution with the forsterite-fayalite series (for example monticellite CaMgSiO4) or minerals that do form a solid solution, except that it's extremely rare in nature (for example tephroite Mn2SiO4). Here's a comprehensive list of the minerals in the olivine group: <http://www.mindat.org/min-29264.html>

Another example is the pyroxene **group**. So for simple Ca-Mg-Fe pyroxenes, you have the clinopyroxene and orthopyroxene **series**, which consist of the end-members (**species**, if you find them pure) diopside (CaMgSiO6) - hedenbergite (CaFeSiO6) and enstatite (MgSiO3) - ferrosilite (FeSiO3), respectively. Intermediate clinopyroxenes are also called augite.

The distinction is not always clear. For example, the feldspar **group** traditionally has the plagioclase **series** (albite-anorthite, NaAlSi3O8-CaAl2Si2O8) and the K-feldspar **species** (KAlSi3O8, either microcline, orthoclase or sanidine, depending on structure). But in some cases there is a solid solution between albite and K-feldspar, forming the alkali-feldspar **series**. Nature doesn't always behave according to our rules, and it's important to remember that our classification systems work well with ideal systems but break down often.

[Further reading](http://courses.missouristate.edu/emantei/mineralogy/mineral%20classif.html)


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