Saudi Arabia sits on the largest continuous sand sea on Earth and still imports construction sand from Australia and Scotland, because thousands of years of wind erosion have polished its desert grains too smooth to bind with cement. The paradox of a country shipping in the material beneath its own feet is now a fixture of every Gulf megaproject. The post Saudi Arabia sits on the world’s largest sand desert and yet imports sand by the shipload from Australia and Scotland, because the wind-rounde