Mineraloid
Fulgurite
Liesegang (Fulgurite)
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 More mineraloid →
Explore Fulgurite in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
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.