Rocks are famous for staying put. If something is as “solid as a rock,” you assume that it’s not going to change or go anywhere.
But in reality, rocks are always changing and on the move. Nature is constantly recycling them. You see that in mountains, rivers, oceans, volcanoes, and canyons. Even in earthquakes!
Rocks come in about 100 varieties. There are also about 3,500 minerals. Those are the things that make rocks. Together, rocks and minerals pave streets and give color to paints. They decorate jewelry and put “lead” into pencils. Rocks are even in your food. The iron in cereal and chalk in bread help make your bones strong. Rock salt makes food tasty. We also use salt to preserve foods. Rocks are in toothpastes and cosmetics. While rocks may not have supernatural powers, as people used to think, they do affect our lives.
