The term fulgurite comes from “fulgur”, which is equivalent to the word lightning in Latin.
Fulgurites or “petrified lightnings” are metamorphic rocks composed by vitrified silica with elongated cylinder shape. When lightning strikes a sandy ground and spreads through the quartz sand melting and vitrifying the grains, fulgurites form.
This process is possible due to the high temperatures that are reached at the moment of lightning impact.
When the shock occurs, the sand and soil vaporize and the lightning penetrates on the ground bifurcating. The silicon temperature reaches 50.000ºC generating hollow glass tubes between 2 and 50mm of diameter.
The amount of energy concentrated on the point of impact elevate the rock and molten sand along the lightning canal. This generates wonderful hollow glass formations known as Fulgurites.
The color of Fulgurites depends on the composition of the ground and its chemical impurities. Generally, they are of different gray tones, although they can be greenish or take on a reddish or white appearance.
David Hermann made the first documented discovery of a fulgurite in Germany in 1706. Since then, fulgurites have been found in most of the world, even in areas such as Sahara where, at present, there are hardly any lightning strikes. This confirm us that in prehistoric times the environmental conditions were very different from today’s conditions.