The whole world is made of rocks! The Earth's rocky crust was formed millions years ago, and its rocks are always changing. It is full of fascinating minerals, and we use its treasures in hundreds of ways. Did you know that toothpaste contains finely ground rock dust, that the stripes in the Grand Canyon's rocks were once layers of sand at the bottom of the sea, and that robots are examining the rocks on Mars? This Level 2 Reader teaches readers all about the different kind of rocks and minerals, how rocks were shaped, how we use the Earth's mineral resources, and how we can unlock its fossil secrets. The book uses simple text and full-color photographs throughout. With supporting facts, technical vocabulary, vivid maps and charts, and a variety of writing styles and text structures, Scholastic Discover More Readers are tailored to the new era of high expectations. The unique informational text reading levels have been developed and vetted by Scholastic reading experts.