A plastic Missouri fire clay providing “tooth” or texture to clay bodies (such as PSH Raku). Also commonly used to make cob ovens or more massive unfired structures when mixed with sand, straw and water. A finer 50 mesh Hawthorn is also available (used in many PSH cone 6 and cone 10 stonewares).
For more information on Hawthorn, see the Digitalfire.com Reference Library of ceramic materials.