Libyan Desert Glass
In the desert situated in western Egypt and Libya, this glass is scattered over thousands of miles. It is said to have formed due to a meteoric collision some 29 million years ago. Collision resulted in high temperature which melted the silica but it so happened that molten mass cooled rapidly and got converted into glass.
Real interest in this glass began when It was found in the pharaoh Tutankhamen crown as a beetle. This crown is 3000 years old. The designers even at that time were thinking the glass to be a gem.