Silica is the principal ingredient of traditional desert glass found in Egypt’s Great Sand Sea, where natural glass pieces are scattered across the Sahara.
Libyan Desert Glass is a pale yellow to nearly colorless natural glass found mainly in western Egypt near the border with Libya. It consists overwhelmingly of silica, the same chemical compound that forms the basis of ordinary glass. The material occurs as irregular fragments and larger pieces across the desert surface.
Scientists generally agree that an extraordinarily intense heating event formed the glass, but the exact mechanism remains debated. Proposed explanations include an airburst or the impact of a cometary or asteroidal body. The heat would have melted or transformed silica-rich surface material before it rapidly cooled.
The glass is not simply ordinary sand melted by everyday desert temperatures. Its formation required exceptional energy. A polished piece was also used in an ancient Egyptian pendant associated with Tutankhamun, showing that the material attracted human attention thousands of years ago.