From magma hardening to sediments pressing together and pressure forcing changes deep underground, the natural world is made up of thousands of different kinds of rock that are constantly forming and changing. What are the three main rocky types? And how do they take shape? Discover the rock cycle. Extraordinary photos and real-world examples invite readers to explore the rock cycle, while an encyclopedic-entry-style format makes the text approachable and highly browsable. Final comprehension questions engage readers to check what they have learned to reenforce comprehension.