Libyan Desert Glass
Libyan Desert Glass
Comet impact glass! 28,500,000 years old!
Above: Front of the Specimen Card.
In the southeastern spur of North Africa’s Great Sand Sea, there are several fields of luminous, yellow-green glass known as Libyan Desert Glass (LDG). Due to the lack of any visible impact crater, the most likely source is a low-density asteroid or comet airburst explosion leading to the fusion of silica-rich sands roughly 28,500,000 years ago.
An Ancient Explosion
28,500,000 years ago, the skies above North Africa were lit up by an asteroid airburst hurtling through the atmosphere. The intense and immediate heat of this event fused the sands of the desert into a yellow green tektite known as Libyan Desert Glass.
This specimen is an authentic fragment of Libyan Desert Glass. The origin of this material dates back almost 30 million years, to the meteoritic event that created all pieces of LDG we have today. The pieces vary widely in size, shape, and color though most are between 0.75" and 1.5" (2.5-3.5cm) in length.
The glass is enclosed in a classic, glass-topped riker display case. The case measures 4 1/2" x 3 1/2" and comes with a small information card about the specimen and guarantee of authenticity issued by Mini Museum.
Note: We've tumbled these specimens slightly to remove sharp edges, but even though it is 28,500,000 years old it is still glass and there might be a few pointy places. In other words, be careful while handling this specimen.
📸 A large chunk of Libyan Desert Glass
Libyan Desert Glass & Tektites
Libyan Desert glass is classified as a tektite, a type of rock created from the the impact of a meteorite. When the intense heat and pressure of an impact event occurs, it can fuse the surrounding sediments into a new material. In the case of Libyan Desert glass, the sands particles of the Sahara were instantly melted into this beautiful yellow green glass.
Another good example of a tektite would be Moldavite, a glassy green silica found around central Europe. Like LDG, Moldavite was formed from a meteorite impact as well, 15 million years ago.
The power of the impact not only creates tektites; it scatters them as well. The strewn field for Libyan Desert glass is hundreds of miles long, as the material was launched an extreme speeds across the planet's surface during its creation. It was likely still molten in the air during this journey, cooling during its descent to the sands.
Though new pieces of tektites are still being discovered, the total amount of this material is limited. Every tektite found can be traced to a specific impact event millions of years ago and there aren't any more being made. We're fine with that though, since the only way to make a new tektite would be to make a powerful meteor hit the Earth! 😂
📸 Map of the Great Sand Sea. LDG distribution is marked in the shaded section.
Libyan Desert glass can be found distributed across a very wide area. This is due impart to it being flung from the impact site during its creation, but that's not the only theory behind its large distribution.
Some scientists have speculatd that there may have been multiple explosions, increasing the area of effect. Recent surveys of the surrounding watershed have also provided strong evidence for distribution by erosion.
📸 Photo of the Great Sand Sea taken from the International Space Station (Source: NASA http://go.nasa.gov/1NCZMr4)
📸 Figures of early tools made from LDG, "Silica-glass from the Libyan Desert", Nature, 1933
An Ancient Mineral
While the dunes of the Great Sand Sea may seem timeless, during the Early to Middle Paleolithic Era the region was often home to a wetter climate capable of supporting playa wetlands. Further to the south, in what is now one of the least hospitable places on earth, permanent lakes and savanna grasslands supported an even greater abundance of life.
Throughout the region, there is plentiful evidence of multiple periods of early human settlement and their own discovery of Libyan Desert glass. Like flint or obsidian, our ancestors shaped the glass into tools and decorative items.
📸 Image of burial pectoral from Treasures of Tutankhamen, 1972
Paleolithic cultures were not the only ones to use the glass either. In 1997, a minerologist named Vincenzo de Michele identified the material used in jewelry piece from King Tutankhamun's tomb as Libyan Desert glass. The glass was shaped into the body of a scarab centerpiece of a pectoral.
This 18th Dynasty find is unique among the gems of ancient Egypt, as it is the only known use of Libyan Glass. The scarab is part of a twofold representation of the sun-god, which in Egyptian mythology could be represented by both scarab and falcon.
Front of the Specimen Card
Back of the Specimen Card
Kleinmann, B., Horn, P., and Langenhorst, F.. "Evidence for shock metamorphism in sandstones from the Libyan Desert Glass strewn field." Meteoritics & Planetary Science 36.9 (2001): 1277-1282.
Welland, Michael. Sand: the never-ending story. Univ of California Press, 2009.
Fröhlich, F., et al. "Libyan Desert Glass: New field and Fourier transform infrared data." Meteoritics & Planetary Science 48.12 (2013): 2517-2530.