The fascinating world of geology is full of massive rocks, ancient fossils, and colorful crystal formations. In the Geology Encyclopedias series, readers will learn everything they need to know about Earth's rocks, minerals, fossils, crystals, and gemstones, exploring how these materials formed, where they are found, and how they are used today. Aligned to Common Core Standards and correlated to state standards. Encyclopedias is an imprint of Abdo Reference, a division of ABDO.