hornstone

(horn’stén), x. A very compact sili- cio us rock, differing but little from flint. It is usually of a dark color, and occurs in nodular ma es and bands. The term is rarely used, and no distinct line of division can be drawn between flint, hornstone, and chert. Hornstone is used in pottery-manufacture to make the grinding-blocks of flint-mills. horn-swivel (hérn’swiv’l), ». A hook-swivel made of horn.