ball clay

== English == === Etymology === Clay of this kind found in Dorset and Devon, England, used to be cut into balls that weighed 30 pounds. === Noun === ball clay (usually uncountable, plural ball clays) A type of clay that commonly consists of 20-80% kaolinite, 10-25% mica, and 6-65% quartz. === References === Krueger, Dennis (December 1982). "Why On Earth Do They Call It Throwing?" Studio Potter Vol. 11, Number 1.[1] (etymology)