Elbaite is a mineral belonging to the tourmaline group. It has a complicated molecular structure but is made up of repeating groups of sodium lithium aluminium borosilicate. It can include a number of other metal elements as impurities which change its colour.
It was first found on the island of Elba, from where it gets its name. It appears within igneous rocks such as granite. Igneous rocks form during the cooling and solidifying of magma. Granite is mostly composed of aluminium oxide (alumina) and silicon oxide (silica).
White light is a mixture of red, green & blue wavelengths. When it strikes the mineral, some of the light is absorbed and some reflected. The exact chemical composition of the crystal determines which colours are absorbed and which reflected. This is why elbaite can vary in colour so subtly.
By adjusting the sliders in the interactive colour mixer above, you can alter the mix of wavelengths and change the colour of the light. For more information about light and colour please check the further reading at the end of this post. Twig World has a video on Colour.
Questions…
- Name two Group I metals you would find in elbaite.
- Name two earth metals you might find in elbaite.
- Suggest two non-metal elements found in elbaite.
- Where is the island of Elba?
- What are the three most abundant elements in the Earth’s crust?
- What colour do you get if you mix red light with blue light?
- What colour do you get if you mix red paint with blue paint?
Further reading from the blog.
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