Dimensions: 61.7 x 42.7 x 29.6 mm max.
Location: Eastern Sahara, MOROCCO
from Wikipedia, the free encyclopedia
Fulgurites (from the Latin fulgur meaning thunderbolt) are natural hollow carrot -shaped glass tubes formed in quartzose sand or soil by lightning strikes. Fulgurites can also be produced when a high voltage electrical distribution network breaks and the lines fall onto a conductive surface with sand beneath. They are sometimes referred to as petrified lightning. The glass formed is called Lechatelierite which may also be formed by meteorite impact and volcanic explosions. As it is amorphous it is classified as a mineraloid.
The tubes can be up to a couple of centimeters in diameter, and meters long. Their colour varies depending on the composition of the sand they formed in, ranging from black or tan to green or a translucent white. The interior is normally very smooth or lined with fine bubbles; the exterior is generally coated with rough sand particles. They are rootlike in appearance and often show branching or small holes. Fulgurites occasionally form as glazing on solid rocks (sometimes referred to as an exogenic fulgurite).
Fulgurites are a very rare phenomenon. A very large one was found in South Amboy, New Jersey. This was roughly nine feet long with a diameter of three inches (7.6 cm) near the surface of the ground, and tapered to roughly three sixteenths of an inch (5 mm) in diameter at the deepest point recovered.