mineral
Fulgurite
Lechatelierite (Fulgurite / Petrified Lightning)
Hardness of 5.5 to 6 on the Mohs scale, color ranges from greyish-brown to black, vitreous to dull luster, amorphous crystal structure (silica glass tube), no cleavage, specific gravity around 2.2.
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Physical properties
Hardness of 5.5 to 6 on the Mohs scale, color ranges from greyish-brown to black, vitreous to dull luster, amorphous crystal structure (silica glass tube), no cleavage, specific gravity around 2.2.
Formation & geological history
Formed when lightning strikes sand or soil with temperatures exceeding 1,800 to 3,000 degrees Celsius, instantly melting and fusing the silica grains into glassy tubes.
Uses & applications
Used in scientific research to study ancient atmospheric conditions and lightning strikes, and collected as a rare geological curiosity.
Geological facts
Fulgurites are literally petrified lightning. The energy of a lightning strike can vaporize rock and sand, leaving behind hollow glassy tubes that can reach several meters deep into the earth.
Field identification & locations
Found in desert regions and sandy beaches where frequent thunderstorms occur. Collectors look for fragile, branching sandy tubes protruding from dunes.
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