Libyan desert glass

Natural glass Low Internet era

Also known as

Great Sand Sea glasssilica glass

Crystal system

amorphous

Hardness

6 on the Mohs scale

Lustre

vitreous

Colour

Pale yellow to yellow-green

Where it forms

Disputed, and that is the interesting part. It is certainly the product of intense heating of desert sand around 29 million years ago. Whether by a meteorite impact, or by an airburst — an object exploding in the atmosphere without cratering — is unresolved, and the evidence has been argued both ways for decades.

Chiefly from

Great Sand Sea, western Egypt and eastern Libya

Why it is that colour

Trace iron in almost pure silica. The glass is around 98 per cent silica, which is exceptionally high and gives it a very high melting point.

Safety

Safe to handle; sharp if broken.

Where it comes from

Collected from a remote area of the Egyptian and Libyan desert. Export from Egypt is restricted, and the region has had serious security problems, so the supply chain is opaque and much material moves informally.

Historical use

A pectoral in Tutankhamun’s tomb has a carved scarab at its centre, and in 1998 that scarab was identified as Libyan desert glass. The Egyptians had crossed several hundred kilometres of desert to collect it.

Recorded as history and attributed where possible. That a stone was used for something establishes that people used it, not that it worked.

What is attributed to it, and since when

No traditional attribution. Ancient Egyptian use is documented and striking — see below — but as a carving material rather than with recorded symbolism. Modern metaphysical claims are recent and largely borrowed from moldavite.

Described, not endorsed. Dating a claim is not the same as assessing it — but an association that first appears in a book published in 1985 is not an ancient inheritance, whatever the label says. A sincere account of feeling better is compatible with the stone doing nothing — see the placebo effect.

Worth knowing

The Tutankhamun scarab is one of the better facts in this collection. The centrepiece of a royal pectoral, buried in 1323 BC, is a piece of glass created by something falling out of the sky onto the Sahara twenty-nine million years earlier. Whoever collected it had walked a very long way into genuinely lethal desert to find a stone that occurs nowhere else.

The formation debate is still live. Impact glass usually comes with a crater and with shocked minerals; this has some shock indicators and no accepted crater. The airburst hypothesis — an object exploding overhead and radiating enough heat to fuse the sand beneath — remains contested, which is unusual for a deposit this well studied.

Identity checked against IMA-CNMNC master list, June 2025.