firestone

/ˈfaɪərˌstoʊn/
noun
  1. A stone that is hard enough to strike against steel to produce sparks, used for starting fires.
    • The hiker used a firestone and a piece of steel to light the campfire.
    • He struck the firestone against his knife, and a shower of sparks flew out.
    • In ancient times, people carried a firestone to make fire on the go.
  2. A stone that is resistant to heat, used in furnaces or fireplaces.
    • The blacksmith lined the forge with firestone to withstand high temperatures.
    • They built the fireplace with firestone to prevent cracking.
    • Firestone bricks are commonly used in industrial kilns.
Synonyms
What does "firestone" mean? | whatsthatwordmean | whatsthatwordmean