Not exactly Oil Spots in the truest sense, these two variations were concocted and tested along with the rest of my oilspots glazes. Both of these recipes utilize some local dolomitic limestone I found and incorporated into the recipes. If you want to re-create these, using a mix of 1/2 and 1/2 Dolomite and Limestone will get you very close.
Epsilon Phase Iron in Tenmoku
For those of you who are really interested in Oil Spots, there’s an article from 2014 that I think is worth a long look. This particular article was what got me interested in SEM microscopy when I was in Grad School:
Learning from the past: Rare ε-Fe2O3 in the ancient black-glazed Jian (Tenmoku) wares – Nature.com
Ancient Jian wares are famous for their lustrous black glaze that exhibits unique colored patterns. Some striking examples include the brownish colored “Hare’s Fur” (HF) strips and the silvery “Oil Spot” (OS) patterns. Herein, we investigated the glaze surface of HF and OS samples using a variety of characterization methods. Contrary to the commonly accepted theory, we identified the presence of ε-Fe2O3, a rare metastable polymorph of Fe2O3 with unique magnetic properties, in both HF and OS samples. We found that surface crystals of OS samples are up to several micrometers in size and exclusively made of ε-Fe2O3. Interestingly, these ε-Fe2O3 crystals on the OS sample surface are organized in a periodic two dimensional fashion. These results shed new lights on the actual mechanisms and kinetics of polymorphous transitions of Fe2O3. Deciphering technologies behind the fabrication of ancient Jian wares can thus potentially help researchers improve the ε-Fe2O3 synthesis.
John Britt on Iridescent Iron Golds and Shinos
Linda Bloomfield – Science For Potters
Fans of the blog will have noticed a lot more activity of late. It seems like one of my favorite old adages is appropriate: Good things come to those who wait. Rather than over promising on a bunch of ideas I may or may not deliver on, I’ll go with another one of my favorite adages: Actions speak louder than words. That last one seems… pretty appropriate.
In any event, I’ve been working on putting together a recommended books section, and felt like I might as well start with one that I’m in! regardless of that last fact, it couldn’t be more appropriate to what this blog is all about.
A few years ago when I was neck deep in my Lava Oilspot research, Linda reached out and asked me to contribute some images and information for this book. I couldn’t have been happier with how my work and images were presented. It’s got all kinds of useful information on connections between rocks, glazes, ceramics, and chemistry.
It’s thoughtfully put together, and if you’re looking to get a handle on using wild materials or learning more about some clay chemistry, this is a great one to check out.
You can find this book here, or by clicking on the image below.
John Britt explains Ian Currie Systematic Glaze Blend!
Ian Currie systematic glaze blend video!
My favorite way to systematically tweak a ceramic “Base Glaze”. John does a great job explaining it!
He can be followed on YouTube @ https://www.youtube.com/user/johnbrittpottery
And you can find more on his website @ https://johnbrittpottery.com/
Another Yunomi Stand
Yunomi Stand by Matt Fiske