EVERYONE knows what happens to a tree when it gets struck by lightning, but what about when lightning strikes the ground? Given the right conditions, such as sandy soil or a beach, the lightning bolt’s path is scorched vertically into the earth, preserved as a network of delicate, glassy tubes called a fulgurite.
The name was coined in the 19th century – fulgur is Latin for “lightning”. Fulgurites form when lightning melts and fuses mineral grains in sand. Knobbly and branched like tree roots, they can penetrate several metres. Estimates of the energy required to create a fulgurite vary, but the temperature reached is thought to be about 4000 °C.…
