Book excerpt: Texas Rocks is a colorful quick identification guide to rocks and minerals in the State. Identification of rocks and minerals is based on color, hardness, crystal shape, and unique features. The guide provides brief descriptions of the types of rocks, differences between rocks and minerals, and mineral groupings. While accurate identification of rocks and minerals often requires extensive laboratory techniques, many are easily identified by unique combinations of the features listed above. The rocks and minerals in this guide have been chosen specifically because they are either unique to Texas or commonly available and easily identified. This waterproof, pocket-sized quick reference also contains information on proper collection and documentation of specimens you may find, and rules and regulations concerning such activities. Collectors of every level will find this information helpful. This guide is a must-have for anyone who wants a quick and easy way to identify rocks and mineral