What is a desert rose (the gypsum crystal sold in the Sahara)?

A desert rose is one of nature's prettiest accidents. It's a cluster of gypsum crystals that grows into the shape of a rose or a flower, the petals being flat crystal blades fanning out from a centre. The sandy desert colour comes from grains of sand caught inside the crystal as it forms. The first time I hand one to a guest, they almost always assume it was carved — but no chisel touched it.

They form underground, not on the surface. In arid basins where the water table is shallow and rich in dissolved gypsum and salts, slow evaporation forces the minerals to crystallise. As the crystals grow over long periods they trap surrounding sand, producing those characteristic sandy, bladed petals. Around Morocco you find them in the dry, saline ground of the southeast — the Tafilalet, the country near Erfoud and Rissani, and out toward the dunes.

You'll see them everywhere once you reach the desert — piled on market tables in Rissani, offered at roadside stalls near Merzouga, ranging from thumb-sized clusters to pieces bigger than a football. They're genuinely natural and locally collected, so they make an honest souvenir. I just remind guests they're brittle: a desert rose will shed petals if knocked, so wrap it well for the journey home.

I like pairing the desert rose with the region's other geological souvenirs — the fossils of Erfoud — because together they tell the story of this land's deep past, from an ancient seabed to a salty drying basin. Holding a desert rose, you're holding crystallised time. It's my favourite small thing to send guests home with: beautiful, completely natural, and quietly explaining how the Sahara's landscape was made.