mineraloid
Fulgurite
Fulgurite (Lechatelierite-rich fused silica)
Hardness: 6.5 (but very fragile), Color: Typically grey, tan, or white with black/dark inclusions, Luster: Vitreous/Glassy, Structure: Amorphous glass (non-crystalline), Cleavage: None (conchoidal fracture), Specific Gravity: 2.1-2.2
- Hardness
- 6
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Physical properties
Hardness: 6.5 (but very fragile), Color: Typically grey, tan, or white with black/dark inclusions, Luster: Vitreous/Glassy, Structure: Amorphous glass (non-crystalline), Cleavage: None (conchoidal fracture), Specific Gravity: 2.1-2.2
Formation & geological history
Formed when lightning strikes sand, soil, or rock, instantly melting the silica into glass tubes or crusts. The heat can reach over 1,800 degrees Celsius. These can be found in layers of the Holocene era to modern day.
Uses & applications
Primarily used as metaphysical or scientific specimens. Occasionally used in jewelry as a 'space' or 'natural power' aesthetic stone, and for studying prehistoric lightning activity.
Geological facts
Also known as 'Petrified Lightning.' They are often tube-shaped because they follow the path of the electrical discharge into the ground, and the interior is usually a smooth, glassy bore.
Field identification & locations
Identify by its light weight, vesicular (bubbly) or glassy texture, and presence of sand or soil particles fused to the exterior. Often found in deserts or high-altitude mountain peaks where lightning strikes are frequent.
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