The Probert Encyclopaedia of Rocks & Minerals

BUHRSTONE

Buhrstone or burestone is a name given to certain siliceous or siliceo-calcareous stones, whose dressed surfaces present a burr or keen-cutting texture, whence they were much used for millstones. The most esteemed varieties were obtained from the upper fresh-water beds of the Paris basin, and from the Eocene strata of South America.
Research Buhrstone