Find out everything you've ever wanted to know about the rocks and minerals under our feet and deep in the Earth's crust. Budding geologists will love reading about how rocks form, the names of the coolest rocks and minerals, and rare and beautiful gemstones. Packed with weird-but-true facts and tons of cool info, this Level 3 reader explores the incredible world of geology. National Geographic Fact Readers feature the same expert-vetted running text as traditional readers-with a bonus 100 fun facts sprinkled throughout! A fact roundup at the end of each book lets kids review what they've learned. (Plus, they can impress their friends with their rocks and minerals expertise!)