What Are Rocks Made Of?

Book excerpt: A chunk of granite rock may look gray and boring, but take a closer look under a microscope and it's possible to see that the rock is made from billions of tiny colorful grains. Each microscopic grain is a substance called a mineral, and it's minerals that are the ingredients that make up all the rocks on Earth. In this book, readers will learn how different combinations of minerals create different types of rocks. They'll discover that metals, such as gold, are actually minerals that can be found in rocks. And they'll learn that some minerals grow as beautiful shapes called crystals that can be made into precious gemstones such as rubies and sapphires. Filled with information perfectly suited to the abilities and interests of an early elementary audience, this colorful, fact-filled volume gives readers a chance not only to learn, but also to develop their powers of observation and critical thinking. From stunning photographs to high-interest facts, this book makes exploring the topic of rocks and minerals a lively, engaging experience.