Libyan Desert Glass is believed to the result of the impact of a large meteorite, or the result of a significant aerial burst explosion around 28.5 million years ago (dated by the fission track method). They are the purest form of natural glass on earth, containing over 96% silica. They were first discovered by ancient Egyptians as evidenced by a scarab beatle carvings found on the mummy of King Tutankhamun. Today they are found in the deep Saharan desert, two days driving into a militarized zone near the border of Libya and Egypt. The leading theory leans towards an aerial burst ten thousand times more powerful than the Hiroshima nuclear detonation (Boslough). Some pieces have dark streaks; chemical analyses of these inclusions show enrichment by meteoritic elements, such as Osmium, with typical chondritic proportions (Koeberl C.). 

This piece is a pleasant, gemmy yellow and shows small white Cristobalite inclusions (a high temperature silica polymorph). It weighs 23 grams.