There are many different kinds of rocks. But rocks have many things in common, too. All rocks are solid, are made naturally, and are made up of groups of smaller particles and minerals that are stuck together. There are three types of rocks: igneous, sedimentary, and metamorphic. Rocks have been used to make buildings, walls, and roads. In the form of fossils, rocks have taught us many things about the kinds of plants and animals that have lived on Earth.

Dona does not know which is more fun-learning about the world through science, or writing books for children that tell all about it. She is glad she does not have to decide and can do both!