Category:Firestone

Fire"stone` (110), n. Etym: [AS. f flint; f fire + stan stone.]

1. Iron pyrites, formerly used for striking fire; also, a flint.

2. A stone which will bear the heat of a furnace without injury; -- especially applied to the sandstone at the top of the upper greensand in the south of England, used for lining kilns and furnaces. Ure.