From beautiful crystals with the energy to power electronic devices to amazing gemstones incorporated into religious practices across different cultures, the natural world has of thousands of different kinds of crystals and gemstones. How do these hidden treasures form deep underneath Earth's surface? And what physical characteristics and traits do scientists use to classify them? Discover the composition behind famous crystals and gemstones, where they are found, and what they are used for. Extraordinary photos and real-world examples invite readers to explore crystals and gemstones, 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.