Fulgurite
Pronunciation : Ful"gu*rite
Part of Speech : n.
Etymology : [L. fulguritus, p. p. of fulgurire to strike with lightning, fr. fulgur lightning: cf. F. fulgurite.]
Definition : Defn: A vitrified sand tube produced by the striking of lightning on sand; a lightning tube; also, the portion of rock surface fused by a lightning discharge.
Source : Webster's Unabridged Dictionary, 1913