(by Shumadra) Fulgurite is formed when lightning strikes dry quartz sand. The temperature from electrical resistance in the ground can get so high that the sand melts (about and later hardens into fragile tubes of lechatelierite [silica glass].
* I think these are man made* Fulgurite Sphere. Also known as Lightning Glass, these delicate, root-like formations are created when lightning strikes rock, instantly melting and fusing the stone into a preserved model of the lightning.
Petrified Lightning --Fulgurites, or “petrified lightning”, are the glassy trails of lightning strikes left in sandy soil or exposed rocks. As fragile as they are beautiful, fulgurites are the next best thing to holding a lightning bolt in your hand!
Master of lightning When a bolt of lightning hit sand a glass formation is created call a fulgurite. This project is about using this powerful phenomenon of nature to create design objects. By Elliott Dahlgren Straat.