The term “fulgurites” comes from “fulgur”, which is equivalent to the Latin word for lightning.
Fulgurites or “petrified lightning bolts” are metamorphic rocks composed of vitrified silica in the shape of an elongated cylinder. They are created when lightning strikes a sandy soil and spreads through the quartz sand, melting and vitrifying the grains.
This process is made possible by the high temperatures reached at the moment of the lightning strike.
When the shock occurs, the sand and soil vaporize and the lightning penetrates the earth, bifurcating. The temperature of the silicon reaches 50,000°C, generating hollow glass tubes between 2 and 50mm in diameter.
The large amount of energy concentrated on the point of impact causes the molten rock and sand to rise following the beam channel. This generates wonderful hollow glass formations, known as fulgurites.
The color of fulgurites depends on the soil composition and chemical impurities in the soil. Generally, they are of different shades of gray, although they can be greenish in color and even take on a reddish or white appearance.
David Hermann made the first documented discovery of a fulgurite in Germany in 1706. Since that time, fulgurites have been found almost everywhere in the world, even in areas such as the Sahara where, at present, there are hardly any lightning strikes. This confirms that in prehistoric times, environmental conditions were very different from those of today.
