Mineraloid

Fulgurite

Liesegang (Fulgurite)

AI-generated identification · may be incorrect

Hardness: 5.5-6.5 (but very fragile), Color: Brownish-black/Tan, Luster: Vitreous to dull, Crystal Structure: Amorphous (glassy), Specific Gravity: 2.2-2.5

Hardness: 5

Identified April 11, 2026More mineraloid →

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Physical properties

Hardness: 5.5-6.5 (but very fragile), Color: Brownish-black/Tan, Luster: Vitreous to dull, Crystal Structure: Amorphous (glassy), Specific Gravity: 2.2-2.5

Formation & geological history

Formed when lightning strikes sand, soil, or rock, instantly melting the silica into a glass tube or fused mass. This typically happens in deserts or on beaches.

Uses & applications

Primarily for scientific research (paleolightning studies), geological collections, and unique jewelry pieces.

Geological facts

Also known as 'petrified lightning,' fulgurites can reach several meters in length underground, but are difficult to excavate without breaking them.

Field identification & locations

Identify by its hollow tube structure (though this one is an irregular cluster), rough sandy exterior, and glassy interior. Commonly found in lightning-prone sandy areas.