Our jumping-off point was the Bahariya Oasis, a large valley of villages and adobe houses. After the 300-kilometer drive on a two-lane highway through the lifeless desert, the irrigated fields were startlingly green — the last green we would see for some time.

Our Egyptian outfitter, his French partner, and the local drivers and crew make this trip several times every year. They plot their GPS tracks on satellite images downloaded from the web. They never repeat the same route, but offset their trips by enough distance that they explore parts of the desert that have never been crossed before.
February in the Sahara is cool, and the wind blows so hard on the Great Sand Sea that it can be hazy like a marine fog. Our meals here are accompanied with sugarsaturated tea brewed Bedouin-style over an open flame of apricot wood carried from the orchards of Bahariya.
To the southwest, the rolling sand builds to great dunes and the sea rises. Vehicles frequently get stuck and have to be rescued by digging and driving them up special aluminum ramps. It takes a special sailor’s eye to distinguish between a safe hard surface and the treacherous soft sand, especially at 100 kilometers/hour. Arabic, French, and English conversations crackle over the radio, and throbbing Egyptian music plays on the driver’s iPod.

On our third day after leaving the last road, our maps tell us we are within the area where glass has been found. We stop to look. There are pieces of sandstone everywhere, and no plants in sight. It looks strikingly like the surface of Mars, and sand sifts underfoot. The first bits of glass we find are yellow-green jewels that have smooth surfaces sculpted by the incessant wind. We hold them up to the sun to see how the light refracts and scatters. This is probably what the Pharaohs did with their piece, and the Neolithic people before them.
Nine days of geologic exploration and discussion bore fruit. You get to know your colleagues well during long days driving and long nights in camp. Everyone figures out the strengths and weaknesses in one another’s ideas. It would be premature to claim that we solved the mystery, but new friendships and collaborations have emerged, and renewed interest in this scientific mystery has energized debate over this unique glass.