These are fully illustrated with color photographs, comprehensive field guides including extensive descriptions covering appearance, habitat, range and much more! A key by color arrangement plus color illustrations of each rock and mineral are two features of this basic guide. Perfect for mountain climbers and hikers, this valuable reference covers more rocks and minerals in North America than any other available guide. 794 full-color photographs depict all the important rocks, gems, and minerals, in many variations of color and crystal form, and the natural environments in which they occur; written descriptions provide information on field marks, similar rocks and minerals, environment, areas of occurrence, and derivation of names. Includes a guide to mineral collecting and a list of rock-forming minerals.