Meaning of "petrified lightning"

vitreous material formed of sand or other sediment fused by lightning.

ful·gu·rite

fo͝ol′gyə-rīt′, -gə-, fŭl′-

fulgurite

(fo͝ol'gyə -rīt ', -gə-, fŭl'-)
n.
A thin, generally tubular body of vitreous rock produced by rays that strike and then fuse dry sandy soil.

[Latin

fulgurite

ˈfʌlɡjʊˌraɪt

fulgurite

( fʌlɡjʊˌraɪt )
n
(Minerals) a tube of vitreous mineral matter that is found in sand and rock, formed by the action of lightning
[C19: from Latin