Clay Underground - articles about clay mining, processing, and testing: Prospecting for Clay - a practical guide by geologist Ralph S. Mason, True to the Seam by Charles Counts, Variables in Raw Materials by Jonathan Kaplan, Mining and Processing Pine Lake Clay by Ann Powers, Procedures and Testing for Potters' Ceramic Clays by Paul Buckles, Quality Control Program for Refractory Raw Materials by D.B. Duewel and W.D. Fitzpatrick, Testing Kaolin by John T. Callahan, Standard Methods for Testing Raw Materials, Buyer Beware! by Richard P. Isaacs. Twelve Western Washington Potters. Firing with Solar Energy by Harriet E. Brisson. The Bauhaus Pottery by Rose Krebs. A Letter from Gerhard Marcks to Rose Krebs. A Dornburg Apprentice by Rose Krebs. Natural Material Ash Glazes by Marge Schweizer. Peter Sabin. Reflections on Hamada by Susan Peterson.