mineral

Fulgurite

Lechatelierite (vitreous silica tube)

Hardness: 5.5 to 7 on the Mohs scale. Color ranges from grey, tan, black, to white depending on the melted soil composition. Luster: Vitreous to glassy internally, dull or sandy on the exterior. Structure: Hollow, glassy tubes or crusts formed by lightning fusion of sand or soil.

Hardness: 5
Luster: Vitreous to glassy internally, dull or sandy on the exterior

Identified July 29, 2026More mineral →

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Physical properties

Formation & geological history

Formed instantly when a high-voltage lightning bolt (typically >100,000 amperes) strikes silica-rich sand or soil, instantly melting and vaporizing the material at temperatures exceeding 1,500 to 2,000 degrees Celsius, which then rapidly cools.

Uses & applications

Collected by researchers, mineral collectors, and used in educational displays. Also studied to understand ancient atmospheric conditions and lightning strikes.

Geological facts

Fulgurites are sometimes referred to as 'fossilized lightning.' They can be extremely fragile and are often found buried in sand dunes or deserts.

Field identification & locations

Look for hollow, fused tubes or crusts of sand grains cemented together, often found in sandy deserts, beaches, or high-altitude mountain peaks prone to lightning. Handle with extreme care as they are delicate.