Sub-titled How and Where to Find Minerals and Gem Stones in the United States, this is much more than a guide. The author provides considerable information of a technical and scientific nature on classifications under the specific chemical families as the simplest approach; on field identification, based on the geologic timetables and the three basic types of rocks. He discusses geologic maps as field aids and how to use them to best advantage. A very practical and complete hobby book for the amateur collector.