It’s all down to the Mica!

I’ve posted a couple of pictures lately showing water in the clay pits here in central Cornwall of the most surreal and vivid blue.  Several people have asked the question, what makes the water this beautiful yet rather surreal blue/green/turquoise colour?  I thought it must be down to minerals or chemicals left over from the clay workings.  I was right in one sense, it is a mineral but not the copper I suspected.

I gave Imerys, the company that operates the china clay works, a call and spoke to Chris Varcoe. He told me the water in the bottom of the pits is a mixture of china clay, water and mica.  Mica is what’s left over when the china clay, or kaolin is separated from the decaying granite rock using high pressure water.  We’ve all seen mica, it’s what they use to make glitter and is a key ingredient used in the billion dollar beauty industry.  Unfortunately that mica doesn’t come from the clay pits of central Cornwall, it’s a waste product here.  The mica used in the cosmetics industry is largely mined in India, often by children.

Mica is a highly reflective mineral as we’ve all seen and when you mix it with china clay in suspension, it reflects light giving the water this vivid surreal colour.  Water reflecting light is what makes the ocean blue, mix in some mica and a bit of china clay and the reflectiveness is greatly enhanced.

For those of you with a scientific bent, the mica group of sheet silicate (phyllosilicate) minerals includes several closely related materials having close to perfect basal cleavage. All are monoclinic, with a tendency towards pseudohexagonal crystals, and are similar in chemical composition. The almost perfect cleavage, which is the most prominent characteristic of mica, is explained by the hexagonal sheet-like arrangement of its atoms giving the mica its reflective properties.

It’s worth noting that this mixture of china clay in suspension and mica is a little like quicksand and extremely dangerous if you find yourself trying to swim in it hence the danger keep out signs and barbed wire fences everywhere.  A timely reminder to an inquisitive photographer who might be tempted to get a little too close. ;-)

_1AT556970mm f/22 1/15 sec. ISO-100

40 responses

  1. Lovely pictures and what a amazing color the water has. Also very instructive :)

    February 19, 2014 at 10:59 pm

    • Thank you Ellen! :-)

      February 19, 2014 at 11:01 pm

  2. Wow! That is some BLUE water!

    February 19, 2014 at 11:02 pm

    • I think perhaps people were thinking Photoshop when I posted before so I thought I’d better explain. :-)

      February 20, 2014 at 7:52 am

  3. You might be sitting on a goldmine, Adrian :)

    February 19, 2014 at 11:15 pm

    • Ahh wouldn’t that be nice.. :-)

      February 20, 2014 at 7:56 am

  4. Thanks for the lesson. I love stuff like this to go with the gorgeous shot!

    February 19, 2014 at 11:35 pm

    • Thank you Gunta. Glad you enjoyed the science bit. :-)

      February 20, 2014 at 7:57 am

  5. Mrs. P

    Fascinating…particularly the quicksand quality.

    February 20, 2014 at 12:49 am

    • The china clay workings are an endless source of fascinating info. I’m looking forward to learning a lot more, taking pictures and posting. Watch this space.. ;-)

      February 20, 2014 at 8:09 am

      • Mrs. P


        February 20, 2014 at 12:48 pm

  6. Cool shot, great color. How about that mica!

    February 20, 2014 at 12:57 am

    • Thank you Mike. It’s quite a substance.

      February 20, 2014 at 8:10 am

  7. I like Mica . . . no, wait . . . that’s Myka on Wherehouse 13.


    February 20, 2014 at 2:57 am

  8. It does make for a striking coloured body of water. Very interesting post, Adrian!

    February 20, 2014 at 3:43 am

    • Thank you Karen! Glad you found it interesting /:-)

      February 20, 2014 at 8:11 am

  9. Very informative notes :) And it’s one superb image.

    February 20, 2014 at 3:48 am

    • Thank you very much Sreejith! Much appreciated.

      February 20, 2014 at 8:12 am

  10. Lovely image Adrian…..but do you understand what you wrote in your 5th paragraph 😉

    February 20, 2014 at 6:56 am

    • Thank you Mark. I did do a fair bit of chemistry covering the structure of atoms and the different qualities these structures give substances so I did get a handle on it.. just! ;-)

      February 20, 2014 at 8:15 am

      • Fair enough…..and good job with the research 😊

        February 20, 2014 at 9:39 am

  11. Interesting facts. I had never heard of Mica or what it does to water. That blue colour is amazing. I remember the first time I went to the mountains in Austria, when I was young.Those mountain brooks had an enigmatic colour too, but not that intense.

    February 20, 2014 at 11:34 am

    • I’m glad you found the post interesting Anne Christine. I hope to do a bit more photography around the clay pits so watch this space. There is so much interesting history. I’m very curious about the single gravestone in the picture I posted a couple of days before this one. I couldn’t read the inscription and it was off limits. I will need to do some research on that one. :-)

      February 20, 2014 at 5:20 pm

      • Looking forward to it, Adrian. Your posts are always inspiring and invigourating!

        February 20, 2014 at 6:08 pm

      • Thank you! :-)

        February 20, 2014 at 6:52 pm

  12. Beautiful shot, Adrian! Wow, that color is gorgeous! :)

    February 20, 2014 at 7:20 pm

    • Thanks Camilla! Much appreciated! :-)

      February 20, 2014 at 8:55 pm

  13. Outstanding!!
    Thanks for the information, Adrian.

    February 20, 2014 at 8:26 pm

    • Thank you so much Isable! :-)

      February 20, 2014 at 8:54 pm

  14. Well, you learn something everyday, thanks for that Adrian! – hope you are keeping well done there in Cornwall.

    February 20, 2014 at 10:04 pm

    • You’re very welcome and thank you Scottie, yes I am. I hope the same for you up in Essex!

      February 20, 2014 at 10:19 pm

  15. So interesting, Adrian. Thanks for doing the research. :) I do love that photo.

    February 20, 2014 at 10:37 pm

    • Thank you Sylvia! :-)

      February 20, 2014 at 10:57 pm

  16. Informative post… intriguing landscape.

    February 21, 2014 at 2:08 am

    • Thank you John, it’s like another world up there amongst the clay workings.

      February 21, 2014 at 1:52 pm

  17. I remember marveling over mica sparkles in the sandbox, as a kid:) Another gorgeous image.

    February 21, 2014 at 2:41 pm

    • Thank you Elena. Yes it’s an amazing substance creating such wonderful colour amongst this very badly scarred landscape. :-)

      February 21, 2014 at 6:49 pm

  18. I really like the brilliant blue water in the lake and those subtle sun rays in the distance. Overall, a well balanced (composed) photograph. Glad I stumbled upon your photographic site.

    February 22, 2014 at 8:52 pm

    • Thank you Spencer. I really appreciate your visit and your comment!

      February 22, 2014 at 9:16 pm