mineraloid

Fulgurite

Luechatelierite (SiO2 glass)

Hardness: 6.5 (Mohs scale), Color: Dirty tan, grey, or black. Luster: Vitreous core with a sandy, rough exterior. Crystal structure: Amorphous (glassy). It is low density and often hollow.

Hardness: 6
Color: Dirty tan, grey, or black
Luster: Vitreous core with a sandy, rough exterior

Identified March 18, 2026More mineraloid →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Hardness: 6.5 (Mohs scale), Color: Dirty tan, grey, or black. Luster: Vitreous core with a sandy, rough exterior. Crystal structure: Amorphous (glassy). It is low density and often hollow.

Formation & geological history

Formed when lightning strikes sand, soil, or rock, instantly melting and fusing the silica into a hollow glass tube. This happens at temperatures exceeding 1,800°C (3,270°F).

Uses & applications

Primarily used for scientific research into paleo-lightning and atmospheric conditions, as well as for unique jewelry and metaphysical specimen collecting.

Geological facts

Commonly known as 'Petrified Lightning.' They are extremely fragile and are often found mirroring the branch-like path of the lightning bolt through the ground.

Field identification & locations

Identify by its unique carrot-like or hollow tubular shape with a glassy internal texture. Found in high-lightning areas like deserts (Sahara) or high coastal dunes (Florida).