Crystals, Rocks, and GemstonesA beautifully illustrated, entertaining, and educational guide to the world's crystals, rocks, gemstones, and other geological phenomena from the acclaimed author of What We See in the Stars. A beautifully illustrated, entertaining, and educational guide to the world's crystals, rocks, gemstones, and other geological phenomena from the acclaimed author of What We See in the Stars. Rocks and minerals have captivated the human imagination for centuries.