What are the three types of rock and how do they form? Where was the oldest fossil found? What are minerals used for? Why are gems so rare and expensive? Become a Rock Explorer and discover the answers to all those questions! With simple, easy-to-understand text, these books are perfect for young explorers keen to understand the world around them. Awesome photography captures detailed rock formations, ancient fossils, different types of minerals and sparkling gems, and a glossary page helps explain tricky new terms.