Firestone
Pronunciation : Fire"stone` (; 110)
Part of Speech : n.
Etymology : [AS. f flint; f fire + stan stone.]
Definition : 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.
Source : Webster's Unabridged Dictionary, 1913