<p>I think the commenters have identified the issue. Halite does not have perfect cleavage along the {110} plane. As recorded in <a href="http://www.webmineral.com/data/Halite.shtml#.WV40FlGQxpg" rel="noreferrer">Mindat</a>, Halite has perfect cleavage alone {100}, {010}, and {001}. This makes sense, as Halite is a cubic mineral (fcc), these are the planes you would expect it to cleave on. </p>

CC BY-SA 4.0
2022-10-08T00:13:39.030Z
[This does control the cleavage direction but there are other cubic minerals where the ion sizes and charge mean the cleavage is stronger in different directions. A good example is fluorite, calcium fluoride, which often forms cubic-shaped crystals but has octahedral cleavage.](https://earthscience.stackexchange.com/a/10634/6031)
uhoh
CC BY-SA 4.0
2022-10-08T00:17:00.003Z
https://i.sstatic.net/OqmOm.png from https://aflow.org/prototype-encyclopedia/ABCD_cF16_216_c_d_b_a.html
uhoh
CC BY-SA 3.0
2017-07-06T13:02:37.547Z
2017-07-06T13:02:37.547Z
Microscone
<p>Why doesn't it cleave nicely along the (100) or (010) or any other planes? What determines its cleavage plane? I know it has something to do with the fact that it crystallizes in face centered cubic  system but I don't understand why things happen the way they do.</p>

CC BY-SA 3.0
2014-06-01T18:24:06.540Z
Fun fact: I keep getting up-votes but no answers.
Tamás
CC BY-SA 3.0
2014-06-02T13:40:18.183Z
I think the fcc that you mention is the key. I can imagine it in my head, but hard to explain. Try drawing an fcc crystal on paper and plotting the 110 plane - it will cut diagonally across the side of the face-centered cell. By extrapolation, I would also expect cleavage on 101 and 011 planes.
winwaed
CC BY-SA 3.0
2014-06-02T15:36:41.013Z
According to mindat.org it has perfect cleavage on {001}. Do the curly brackets include those planes mentioned by you?
Tamás
CC BY-SA 3.0
2014-06-04T19:49:38.610Z
Yes. So where did you get the (110) from?
winwaed
CC BY-SA 3.0
2014-06-05T08:28:00.040Z
My mineralogy professor who has a PhD in geology... Don't ask
Tamás
<crystals><mineralogy><crystallography>
Why does halite have perfect cleavage at the (110) plane?
Tamás
# Why does halite have perfect cleavage at the (110) plane?

(Asked by: username_0 on 2014-06-01)

Why doesn't it cleave nicely along the (100) or (010) or any other planes? What determines its cleavage plane? I know it has something to do with the fact that it crystallizes in face centered cubic system but I don't understand why things happen the way they do.

**Tags:** crystals, mineralogy, crystallography

> **Comments:**
> **username_0**: Fun fact: I keep getting up-votes but no answers.  
> **username_1**: I think the fcc that you mention is the key. I can imagine it in my head, but hard to explain. Try drawing an fcc crystal on paper and plotting the 110 plane - it will cut diagonally across the side of the face-centered cell. By extrapolation, I would also expect cleavage on 101 and 011 planes.  
> **username_0**: According to mindat.org it has perfect cleavage on {001}. Do the curly brackets include those planes mentioned by you?  
> **username_1**: Yes. So where did you get the (110) from?  
> **username_0**: My mineralogy professor who has a PhD in geology... Don't ask  

---

## 1 answers

### Answer by username_2 on 2017-07-06. Score: 5

I think the commenters have identified the issue. Halite does not have perfect cleavage along the {110} plane. As recorded in [Mindat](http://www.webmineral.com/data/Halite.shtml#.WV40FlGQxpg), Halite has perfect cleavage alone {100}, {010}, and {001}. This makes sense, as Halite is a cubic mineral (fcc), these are the planes you would expect it to cleave on.

> **Comments:**
> **username_3**: [This does control the cleavage direction but there are other cubic minerals where the ion sizes and charge mean the cleavage is stronger in different directions. A good example is fluorite, calcium fluoride, which often forms cubic-shaped crystals but has octahedral cleavage.](https://earthscience.stackexchange.com/a/10634/6031)  
> **username_3**: https://i.sstatic.net/OqmOm.png from https://aflow.org/prototype-encyclopedia/ABCD_cF16_216_c_d_b_a.html  

---

