Sand seems like the simplest material in the world — until you look closely. Saharan sand is a mix of quartz, limestone and volcanic particles, generally between 0.0625mm and 2mm across, and its exact composition changes from one erg to the next depending on the rock it originally came from.
How It Formed
That sand is the product of millions of years of erosion: wind and temperature swings slowly breaking down rock into ever finer grains, which are then carried and sorted by the wind into the dune fields we see today. The tall, sweeping dunes of Erg Chegaga are, in a very real sense, a multi-million-year-old landscape still being reshaped every single day.
More Than Just Dunes
Desert sand is also a genuine resource. It is used in construction, in glass-making, in water filtration systems, and increasingly in agriculture and solar panel manufacturing. That demand has a downside, though — large-scale sand extraction elsewhere in the world has been linked to erosion, biodiversity loss and desertification, a reminder that even a seemingly endless resource has limits.
Walking On It
None of that changes how it feels underfoot at sunset, when the whole erg turns gold and the sand is still warm from the day. It is worth taking a moment, on any trip, just to notice it.
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Curious to experience it yourself? Explore our desert treks in Morocco.