Halite – Day 23 of the Mineral Advent Calendar

This holiday season, why not get a mineral every day instead of chocolate? Today’s mineral is Halite find out more about it below..

It’s December 23rd and if you have finished work and are lucky enough to have tomorrow off, you might now very be….

If so, please be safe when driving back; if the rest of the country is anything like Devon tonight the roads are pretty wet!! Fortunately (or not, depending on how much rain you get) that means we probably won’t see any of a mineral that is usally EXTREMELY common this time of year – no not Ice, but it’s related – that is rock salt, used in grit to keep the roads safe. Salt is most definitely a mineral, as anyone who has ever been to a salt mine can attest. Rock salt, more properly called Halite when in it’s mineral form, is something that although we may be more familiar with it on the kitchen table, it is essential for safe driving at this time of year. So stay safe on the roads if you are driving home tonight, and check out this amazing microscope image of a Halite crystal taken by Dr Natasha Stephen in Plymouth University Electron Microscopy Centre.

A lovely Halite crystal photograph taken by Dr Natasha Stephen at the Plymouth University EM centre.

A lovely Halite crystal photograph taken by Dr Natasha Stephen at the Plymouth University EM centre.

Halite:
Chemical formula: NaCl
Colour: Colourless, white, yellow, red, purple or blue
System: Isometric
Hardness (Mohs):
Can you find it in the UK? Er yes! (In fact it is still mined in Cheshire)

Cheshire's salt mines are still very much active! Image from the BBC.

Cheshire’s salt mines are still very much active! Image from the BBC.

Halite is a common mineral all over the world and although I have been talking about it in it’s mineral sense (that can be mined – a type of mineral called an evaporite), let’s not forget that you can also get halite when it is exsolved out of sea water! This can cause Halite to crystallise in sheltered spots around the coast, so keep an eye out for these little white-pink cubes, you may find it more easily than you think!

For more information about Halite please visit the MinDat website.

Ice – Day 7 of the Mineral Advent Calendar

This holiday season, why not get a mineral every day instead of chocolate? Today’s mineral is Ice find out more about it below..

So at this point you might be looking at the screen and going – ‘ICE?! That’s not a mineral!’ But in fact it is – it’s just a mineral with a really low melting point, so it’s one of the few minerals that you can not only see commonly in its natural form, you can also synthesise it too! Yes, you can create your own mineral synthesising environment by filling a tray with water and putting it in your freezer. And although this is still ‘ice as a mineral’, because you force the mineral to grow in an unnatural environment, it rarely forms the kind of structures you would associate with natural ice crystals. And as it is #MicroscopyMonday, what better way to look at ice than through a microscope.

There are two types of ice that I relate to the season; the first is natural, falls from the sky and I very rarely get to see in the UK. Yes I am talking about snow, and if you have never seen a snowflake through a microscope you are in for a treat, because they are exceptionally beautiful.

Absolutey gorgeous photos of the stellar dendrites form of ice, please visit Kenneth Libbrecht's webpage form more spectacular imagery.

Absolutey gorgeous photos of the stellar dendrites form of ice, please visit Kenneth Libbrecht’s webpage form more spectacular imagery.

The second type of ice we see commonly at this time of year comes out of tub in your freezer (my favourite is chocolate – obviously!) and this photo is one taken by Steve Furzeland for some research being done at the Electron Microscopy Centre in Plymouth – yes, it’s ICE CREAM!

A great image of an ice crsytal in Ice Cream, taken by the Plymouth University Electron Microscopy Centre.

A great image of an ice crsytal in Ice Cream, taken by the Plymouth University Electron Microscopy Centre.

 Ice:

Chemical formula: H2O
Colour: Colourless to white
System: Hexagonal
Hardness (Mohs):
Can you find it in the UK? Er, yes? Seriously, you even have to ask!!

Ice. It gets everywhere! (image from prettymyparty.com)

Ice. It gets everywhere! (image from decoration idea supplied on prettymyparty.com)

There are many forms of ice beyond the branching six-sided (because they are hexagonal – get it?) shapes so as I say go back and look at Kenneth Libbrecht’s website for more forms.

For more information about Ice please visit the MinDat website.

Check out more Plymouth University Electron Microscopy images here.