Where Does Sand Come from?
Sand is made from tiny grains of rocks and minerals. Almost every grain of sand was once part of a big rock. Heat and cold caused cracks in the rocks, and wind and water chipped away at them.
Sand is made when rocks or shells break into tiny pieces. Over time, rock is broken down by water, wind, and ice. It takes thousands or millions of years to create sand. Wind, water (rain), ice, and even the process of freezing and thawing work on mountains. Pieces of rock break off the mountain. These pieces fall because of gravity. Water and wind may carry them far away.
In fast-moving streams, water tumbles stones along, slowly grinding them into sand. The sand accumulates in the lower parts of the stream. At the sea shore, waves crashing against the cliffs break up the rock into grains of sand, forming sandy beaches. Volcanic lava created the black sand of a beach in Hawaii.
Bits of coral and sea shells are broken down to form the sand on many tropical islands. Some sand comes from the calcium (a mineral) in seaweed. Sand can be different colors. That’s because shells, rocks, and minerals are different colors. Sand on beaches can be black, white, brown, green, yellow, or even pink!