Texas has a great variety of rocks and minerals some are common and others are not. This book is designed to aquaint you with some of them and to tell you in a nontechnical way what they are like, some of the places where they are found, and how they are used. Although we do not know exactly how all of the rocks and minerals formed, some of the ideas about their origin are mentioned. If you would like to learn more about rocks and minerals in general, the names of several reference books are listed on page 100.