mineral

Fulgurite

Lechatelierite (Silica glass tubes)

Hardness: 6-7 on the Mohs scale; Color: Brown, black, gray, or tan; Luster: Vitreous to dull; Structure: Amorphous glass tube with rough exterior sand grains fused together; Cleavage: None (fractures conchoidally); Specific gravity: 2.1 - 2.2

Hardness: 6-7 on the Mohs scale
Color: Brown, black, gray, or tan
Luster: Vitreous to dull

Identified August 6, 2026More mineral →

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Physical properties

Formation & geological history

Formed when lightning strikes sand or soil, instantly melting and fusing the material at temperatures exceeding 1,800 degrees Celsius (3,272 degrees Fahrenheit). Can range in geological age from recent to millions of years.

Uses & applications

Used primarily by scientific researchers studying ancient climate and lightning strikes, and collected as unique mineral specimens by enthusiasts.

Geological facts

Fulgurites are often called 'fossilized lightning.' They can sometimes be found extending several meters deep into sand dunes.

Field identification & locations

Found in sandy deserts, beaches, or high-altitude mountain peaks where lightning strikes are frequent. Identified by its tubular, glassy interior structure and rough, sand-encrusted exterior.