Our civilization is literally built on sand. People have used it for construction since at least the time of the ancient Egyptians. In the 15th century, an Italian artisan figured out how to turn sand into transparent glass, which made possible the microscopes, telescopes, and other technologies that helped drive the Renaissance’s scientific revolution (also, affordable windows). Sand of various kinds is an essential ingredient in detergents, cosmetics, toothpaste, solar panels, silicon chips, and especially buildings; every concrete structure is basically tons of sand glued together with cement.
Sand—small, loose grains of rock and other hard stuff—can be made by glaciers grinding up stones, by oceans degrading seashells, even by volcanic lava chilling and shattering upon contact with air. But nearly 70 percent of all sand grains on Earth are quartz, formed by weathering. Time and the elements eat away at rock, above and below the ground, grinding off grains. Rivers carry countless tons of those grains far and wide, accumulating them in their beds, on their banks, and at the places where they meet the sea.
Apart from water and air, humble sand is the natural resource most consumed by human beings. People use more than 40 billion tons of sand and gravel every year. There’s so much demand that riverbeds and beaches around the world are being stripped bare. (Desert sand generally doesn’t work for construction; shaped by wind rather than water, desert grains are too round to bind together well.) And the amount of sand being mined is increasing exponentially.
Though the supply might seem endless, sand is a finite resource like any other. The worldwide construction boom of recent years—all those mushrooming megacities, from Lagos to Beijing—is devouring unprecedented quantities; extracting it is a $70 billion industry.