These stones are located in only one particular area, in a specific
region of the Great Erg or sand sea. It is said that there is an
enormous amount of this yellow glass in that area, found between a
series of dunes in the desert.
Libyan desert glass, 29 million
years ago was probably formed when an asteroid or comet hit the surface
of the earth like a huge atomic bomb, unleashing enough destructive
force to not only liquefy the rocks, sand and dirt at ground zero, but
to splash the molten, mixed material up into the wispy outer atmospheric
regions.
Perhaps some escaped Earth's gravity altogether; the
rest plummeted back in a rain of fire and molten glass. The crater
marking the original impact site has not been discovered - no doubt it
is under millions of pounds of sand. But wherever the original impact
responsible for Libyan Desert Glass occurred, the results came to rest
in the wilds of the Western Egyptian desert.