A couple of weeks ago we got an email from one of our readers who is currently studying how to make ceramics and porcelain in Iceland. She was wondering about what ashes might give the best colours.
I am not the best geologist around, and instead concentrate on the squiggly stuff on seismometers and bouncing dots from GPS-stations, I thought it might be a fun weekend challenge for our esteemed readers to help her out.
I have edited the emails and put them below. So, hope that you all will have fun!
A bowl of ash
In my work I examine local raw material not from a scientific point of view but more from aesthetic. I use them to colour ceramic objects.
For my diploma project I was interested in working with basaltic volcanic ashes as I suppose they are rich in iron (which gives me a colour).
As I know basically nothing or almost nothing about geology, I have problems with telling which material is which and where to find the material I could work with.
This is where I would need some help.
This weekend I went to Seyðishólar. I picked up some red pumice rocks, but the problem is that even if I grind it very well, I´m not able to get super fine powder.
This is when I stumbled upon your article and found the pictures of volcanic ash layers (which is called tephra I guess, from the article I read on your website).
I tried to find this kind of layer near Seyðishólar but the ground was frozen so I could pick anything up.
What I see in the picture below (the quarry in Seyðishólar) is not tephra right, or is it? If not, are those different lava rocks?
If I would like to find tephra layers, would you recommend looking for some open earth profile (possibly in Seyðishólar) or just try to dig a hole somewhere in this area? (Editor’s question: Or are there other better areas?)
And one more question about the method of recognizing the layers (just by curiosity). Are layers of tephra recognized by the order of volcanic eruptions and then also colours? Are there any other factors involved?
Points for answers
I will award points for good answers, good suggestions, and Editor’s Choice Award points for answers that are “out there, but helpful”. I will declare a winner at the end of the next article we publish.