Notes from my time writing â€œBaba Ali and the Clockwork Djinnâ€ and fun tidbits.
All right.Â I’ll admit it.Â This bit of research was so awesome I had to includeÂ desert glassÂ in the book even though I know that geographicallyÂ this phenomenonÂ does not occur in the Arabian desert where my novel takes place. Also of note was that this form of desert glass wasn’t even discovered until 1932.Â Of course, the nice thing about Steampunk is that this is re-written history, so at the very least, from a time perspective, I think I’m off the hook.
What I am talking about is generally known as Libyan Desert Glass (LDG).Â Â It is something of a geological mystery.Â In 1932, a desert survey expedition travelling in the corridors between the dunes (saifs) in the Sand Sea on the frontier between Egypt and Libya discovered, scattered about on sand, transparent to translucent pieces of a pale yellow-green glass.Â It was dated at over 28.5 million years old.
So what is so strange about LDG that it excites so much intellectual curiosity? LDG is an amorphous glass of silicon dioxide, more commonly found in its crystalline form as quartz. Small pieces of silica glass are often found associated with lava flows which cool suddenly as they pour into the sea. The silicon in the lava freezes, forming an amorphous mass that resembles broken glass. These materials are about 75% silica, the rest being made up of crystals of quartz and oxides of aluminium and iron. Desert glass, by contrast, is 98% pure silica, the purest natural glass in the world.
How LDG was formed in the first place is a mystery. Why did it form here and nowhere else? The composition and structure of the glass is consistent with the scenario that is was formed from melted dune sand, and then cooled over a period greater than 24 hours in an earth atmosphere.
Pretty awesome mystery, yes?