Mineral Diversity

What is a mineral?

Minerals are made of elements (these are the tiny building blocks of non-living things) arranged in a specific way. The specific way that elements are arranged in minerals makes regular shapes, a bit like scaffolding around a building. These regular shapes are called crystals.

Minerals are naturally occurring (not made by humans), inorganic (not alive) and solid (not liquid, like water or gas, like air). To learn more about minerals, and how they are like cakes (!) visit our learning zone.

A mineral is different from a rock; a rock is made of more than one mineral.

How does diamond look?

The crystals in minerals make different shapes, depending on which elements are making up that mineral. For example, diamond is a mineral, made of the element carbon. The carbons all connect to four other carbons, making a regular shape, as seen in the picture.

 

image showing a diamond's carbon structure

Each black circle is one carbon. The lines show how the carbons are joined together in diamond.

 

Other mineral shapes: build your own!

Diamond crystals form in a shape called isometric. This means that the pattern would fit inside a cube. There are seven different types of crystal shape; have a go at building them using the patterns below and see if you can describe them! What makes one shape different from another?

Instructions:

  • print out one of the shapes below (preferably onto card, or thick paper)

  • cut out the outline (don’t cut off the tabs!)

  • fold along the lines, then try folding your crystal shape up to check it works

  • if any parts don’t fold easily, fold those lines down more firmly

  • once you are happy, add glue to the white tabs, and stick your 3D crystal shape together!

  • hold your glued shape until it sets

  • compare your 3D crystal shape to the other shapes – what makes this one different? Are some of them more similar to others?

If you would like to try folding a more complicated example, you can find many more patterns here! Many thanks to David Barthelmy at webmineral.com for allowing us to use these 3D mineral patterns.

Finally, some materials which we might use as gems do not have a regular shape, and so are not true minerals. One example of this is Agate – Agate slices are very pretty with their irregular, swirling colours. However, Agate is not a mineral as it is made up of many different crystals: this is called polycrystalline.

 

image of agate a polycrystalline

Agate is polycrystalline.

 

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