Book excerpt: From exploring the basic principles of geology to starting a rock and mineral collection, The Practical Geologist is the perfect introduction to the world of earth science. Beginning with a history of the earth's formation and development, this book explores the substances that compose the planet, movements within the earth, the surface effects of weather and water, and underground landscapes. It shows you how to search for, identify, and extract samples of various rocks and minerals, and for each rock and mineral type there is a brief mineralogy and explanation of its locations. There are also sections on mapping, preparing, and curating specimens, and geological sites on the six continents. Packed with more than 200 full-color illustrations, this comprehensive guide is the essential practical companion for natural science enthusiasts everywhere.