• Question: How do quartz crystals (like amethyst and rose quartz) get their different colours?

    Asked by AnabellesThrone to Matthew, K, Jacque, Fiona, Daniel on 6 Mar 2018.
    • Photo: Fiona Macfarlane

      Fiona Macfarlane answered on 6 Mar 2018:

      I asked my brother, who is a geologist and he said that there are two reasons for the different colours. Chemicals can cause different colours, Amethyst for example has traces of iron making it purple. Imperfections and the shape of the crystal can cause light to be reflected in different ways, which makes them appear to be different colours.

Comments

  • Photo: Hazel

    Hazel commented on :

    Yep what @Fiona said is true – amethyst is purple because it has traces of iron in it, but has also been exposed to radiation whilst it is being formed (interestingly citrine – the yellow quartz crystal – is just amethyst that has been heated up again after it has formed, this is often done artificially by people selling crystals). Rose quartz is pink because it has fibres (think like fur or hair) of something called borosilicate. Smokey quartz is quartz that doesn’t have iron in it, but has been exposed to radiation. But don’t worry, just because they were exposed to radiation when they were forming doesn’t mean they are radioactive – they are perfectly safe.