Sand is just rock that has been eroded. Erosion is when wind, water, or other natural agent wears away at rock and takes it to a new place. This take millions of years to happen. As the wind or water etches away at the rock, the pieces of soil or rock that come off get carried to someplace new. Before the sand on beaches formed, everything was just rocks! Over millions of years ice, rain, the Sun, and waves broke down the rocks into tiny pieces and deposited them into the oceans. As the waves hit the shore, the broken up rock gets deposited on the beach! Over millions of years pebbles turn into sand. There are different types of sand like black sand, which has very big grains and coral sand, which is a very fine sand that comes from coral reefs! No matter what type of sand it is, it would not be a beach without sand!