Libyan Glass
Unique, beautiful and a bit mysterious. (The Bus 3.34)
Welcome aboard The Bus!
The Stop
Libyan glass is a natural glass found in the Libyan Desert in the southwestern corner of the Great Sand Sea near the Egyptian/Libyan border. Believed to have been created by a meteorite impact around 28 million years ago, the glass is unique in that it is nearly pure silica - a composition that would require temperatures about 1,600 °C (2,912 °F)1 to form. First mentioned in the writings of the Greek historian Herodotus,2 he described the glass as a ‘yellow stone’ frequently used to make jewellery. Ironically, even though he was writing in the 5th century BCE, Herodotus would have had no idea that nearly 1000 years had passed since the most famous jewel made of Libyan glass had been buried in King Tutankhamun’s tomb.3
Libyan glass is a tektite (from Greek tektos, ‘melted’) - the product of a meteorite impacting into and melting the Earth’s surface. Upon impact, the intense heat and pressure causes terrestrial rocks to liquify and then spray into the upper atmosphere before returning to the surface as solidified glass. The nature of the meteorite event that resulted in Libyan glass has been elusive, with scientists split between either an impact or airburst.4 For most of history, it was thought an airburst was more likely to have formed the glass as no impact crater has ever been found. However, recent research has changed this opinion through the discovery of the presence of an ‘unusual mineral called reidite.’
Only formed during meteorite impacts, reidite is produced when the pressure and heat of the event forces atoms in the mineral zircon into a ‘tighter arrangement’ than normal. Such high-pressure minerals are a hallmark of a meteorite impact, and do not form during airbursts. Additionally, geologists estimate that a 100 megaton airburst should occur on average every 10,000 years, an event that is not supported by the geological record. Consequently, the presence of reidite in Libyan glass indicates that a meteor impact is the ‘only option’ for its creation, despite questions still remaining about the location of the crater, its size and whether or not it has eroded away.
The Detour
Today’s Detour is to Every Sport a Bowling Ball, a short (2:38) deadpan comedy exploring what would happen if - in a number of sports - the ball was replaced with a bowling ball. It’s ridiculous, but done so earnestly it’s genuinely funny.
The Recommendation
Today’s Recommendation is Frank Herbert’s Dune (1965), an epic science fiction novel set in the distant future on the desert planet Arrakis. Inhospitable and barely populated, the planet is of dire importance as it is the only source of melange, or ‘spice’, a drug required for space navigation. The protagonist is the young Paul Atreides, whose family is given control of the planet, who overcomes numerous adversities before attaining his destined messianic role. Filled with a rich combination of politics, religion, ecology, technology, and human emotion, the novel is considered one of the most popular and greatest science fiction novels in history. Arguably much better than either of its film adaptations, the novel is a great, complicated read - and highly recommended.
The Sounds
Today’s playlist is based around … glass: ‘Heart of Glass’ (Blondie, 1978), ‘Walking on Broken Glass’ (Annie Lennox, 1992), ‘Glass Eyes’ (Radiohead, 2016), ‘Glass Onion’ (The Beatles, 1968) and ‘Glassworks: Opening’ (Philip Glass, 1981 (recorded: 2018).5
The Thought
Today’s Thought is from Dune:
‘A process cannot be understood by stopping it. Understanding must move with the flow of the process, must join it and flow with it.’
If you have a thought on this Thought - or any part of today’s issue - please leave a comment below:
And that’s the end of this Stop - I hope you enjoyed the diversion!
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Until the next Stop …
This temperature is hotter than any igneous rock on Earth. Most manufactured, commercial glass contains around 70% silica. High-silica glass (96% content) is used for spacecraft heatshields and specialised chemical glassware. Libyan glass contains over 97% silica - a composition which is difficult to manufacture due to the intense heat required.
Herodotus (ca. 484 BCE - ca. 430–420) was the author of the first narrative history in the ancient world. For more information, see: Herodotus (Britannica).
I had never heard of Libyan glass until I fell into a conversation at a recent dinner. The conversation started when I noticed the woman sitting next to me was wearing a cartouche, which led to a discussion about Egypt, which resulted in one about Libyan glass. Unfortunately, the conversation quickly degenerated from anything interesting (i.e., geological) into the banal (i.e., the supposed ‘power’ and ‘energy’ these pieces of glass supposedly emitted). Oh, well. At least it led to a topic I found interesting - and rather short, too, as there’s not much out there about it. Sources for today’s Stop include: Libyan Glass Mystery Solved (Cosmos) and Libyan Desert Glass (Sothebys).
Meteorite impacts leave craters; meteorite airbursts - like nuclear bombs detonated as airbursts - deposit ‘energy into the atmosphere that can melt surface materials,’ and do not leave craters. And an airburst does not leave a crater.
The Philip Glass piece is performed by Vikingur Olafsson, the pianist on ‘Organ Sonata No. 4 II: Andante [Adagio]’ featured on The Sounds playlist for The Bus 2.14 ‘Brandenburg Concertos’ (paywalled). I only mention this because he is a brilliant colourist - and absolutely worth a listen.
A wonderful post - thank you, Bryan! I've always found glass fascinating, but had never heard of Libyan glass specifically. The Bus is certainly an education!
Dune - YES. Wonderful writing which gets deeper and better the more you get into the series - I'm currently on Dune 3 about to start Dune 4 - loving the intensity and detail of the world building. Oh yeah.