thunderstone

noun3

1. •
   A stone or fossil thought to be, or be caused by, a thunderbolt striking the earth.

   • Thunderstones are sacred to the vodounist, forged as they are by Sobo and Shango, the spirits of thunder and lightning. — 1985
2. •
   A belemnite.
3. •
   (no longer used) A thunderbolt.