Rock Glazes, Geology & Mineral Processing for Potters by Steve Harrison

My principal reason for collecting and processing my own raw materials, an interest that I have pursued over the last 45 years, is two-fold. Firstly, I have a deeply held belief in a theory of locality, which I call the ‘location specific event’ which I have written about elsewhere. Secondly, it is to strike a blow against the trend towards a global pottery style, where a majority of potters around the world end up using all the same ceramic ingredients. An oligopoly of ceramic material manufacturers using the same colours, frits etc.

China clay is sourced from New Zealand, bentonite from Mexico, nepheline syenite from Canada. Where one ingredient is found to be very good, it is shipped all over the world and everyones work has the same basic look and feel. I am happy to seek out ‘inferior’? local raw ingredients for my pots, for my food and for my wine. I think its called character. It certainly won’t be the best in the world, it may not even be very good in comparison to the ‘best’ but it’s what happens here, with this stuff. It’s my belief that if you work with a material long enough you will find a way to express its personality, and beauty.

Some of the chapters include; A Brief Introduction to Geology for Potters, An Overview of Rock Crushers, Flotation-A Remarkable Method Of Refining Useful Minerals. Empirical Blending, a fast method of establishing the alumina silica ratio of your rock, and finding the ‘sweet-spot’ recipe that will give the best result from your rock. There is a basic introduction to Glaze Chemistry and an A3, fold out, colour coded, Periodic Table is included in the back.

Revised edition, March 2003
ISBN 0975053000
Published by Hot & Sticky