Is Libyan Desert Glass a meteorite?
No. Libyan Desert Glass is natural silica glass found in western Egypt, formed about 29 million years ago, probably by the heat of an impact or airburst.
Libyan Desert Glass is a pale yellow to greenish natural glass found in the Great Sand Sea of western Egypt, near the border with Libya. Pieces range from small chips to blocks weighing tens of kilograms. It is almost pure silica, about 98 per cent.
Not a meteorite. It is made of melted Earth material, probably desert sand or sandstone, not of space rock. It contains no metal, is not magnetic and lacks a fusion crust. It is glass, not crystalline rock.
How it formed. Dating shows it formed about 29 million years ago. Its features show that it was produced by extremely high temperatures. It contains grains of reidite, a high-pressure form of zircon, and evidence that zircon broke down at temperatures above about 1,600 °C. Most scientists think it was formed by a meteorite impact or a very powerful airburst. No definite crater has been identified, which keeps the debate alive. Some samples contain traces of meteoritic material.
History. Ancient Egyptians valued it. A scarab carved from Libyan Desert Glass forms the centre of a pectoral jewel found in Tutankhamun's tomb. Stone Age people also used it to make tools.
Collecting. Libyan Desert Glass is popular with collectors and is often faked with industrial glass. Genuine pieces often have wind-polished surfaces, bubbles and swirls. Collecting and export from Egypt are controlled by law.
Like moldavite and other tektites, it is an impact-related material that tells the story of a powerful event.