How is sand formed?

Most of the sand on the world’s deserts and beaches is made from quartz which is the hardest of the common rocks. Some of the gritty grains are formed when chunks of hard quartz are smashed to fragments. In time, the pounding tides, the roaring rivers and the desert winds can break up the hardest of stones.

But most sand starts out in the form of small grains embedded in masses of granite and other lava rocks. Wind and weather wear away the softer rocks, freeing the durable grains of sand to spread over the deserts and beaches.