Natural Glass in the Desert

New Stuff (Robert Twigger)

Robert Twigger, who wrote The Lost Oasis has been posting some interesting pieces on the above blog recently. This one concerns the 29 million year old glass found at the borders of Egypt and Libya (known as Libyan or silica glass).

For some reason the natural glass in the Great Sand Sea of Egypt is always referred to as silica glass which is odd as all glass is made of silica unless it’s plastic…anyway this natural glass is 98% silica which makes it the purest natural glass in the world. Other glasses, such as volcanic obsidians are lower in silica at 75%.

The natural glass of the Sand Sea is found in a large area stretching from just north of the Gilf Kebir to a few hundred km south of Siwa. The area of highest concentration is small but I’ve found small pieces of glass spread over a long but not wide distance. Mainly the glass is confined to four dune corridors- the ones used by cars storming up from the Gilf to Siwa.

The glass was formed by a giant meteorite hitting the earth it is widely believed.

See the above for more.

There's a review of Lost Oasis by Toby Lichtig on the Guardian website.