National Audubon Society (R) Field Guide to North American Rocks and Minerals is a one of the best field guides on the market.  The field guide features 794 full-color images of all the important rocks, gems, and minerals of North America, showing their many variations of color and crystal forms.  The photographs are organized by their subjects' color with a thumb tab index for quick and easy identification. Included in this great guide are twice as many descriptions and color plates as any other rock and mineral guide. The Field Guide to North American Rocks and Minerals offers guidelines for collection procedures, keys to identification and also a mineralogical glossary. The guide provides information on 200 minerals (including 20 classified as gemstones) and 40 rocks, as well as descriptions of the natural environment where they occur. The author, Charles W. Chesterman, is Senior Scientist at the California Division of Mines and Geology and Honorary Curator of Mineralogy at the California Academy of Sciences. National Audubon Society Field Guide to North American Rocks and Minerals is copyright 1979, 24th printing, Jan. 2008 (Publisher, Alfred A. Knopf, New York.) The size of the field guide is approximately 4" x 7 3/4" x 1 1/2" which makes it ideal to carry in a pocket when out in the field. The cover of the book is weather resistant material. List price for the National Audubon Society Field Guide to North American Rocks and Minerals is $19.95.