Everything you need to know about rocks and minerals. All 377 entries, beautifully illustrated with color photographs and helpful visual symbols, provide descriptions and practical information about appearance, classification, rarity, crystal formation, mode of occurrence, gravity of minerals, rock chemistry, and much more. Prefaced by a comprehensive introduction that includes a discussion of formation and chemistry. Glossary and index. 1978, 607 pages, 4-1/2" x 7-1/2", soft cover.