Rocks are made up of a mixture of minerals. Therefore you need to know what minerals and how much of each mineral are in a rock before you can give that rock a name. This has been an obstacle for the student of nature and natural science who just wants to give a rock he has collected a fairly accurate name without having first to study mineralogy. Simple ways of identifying common species of birds, trees, flowers, and many other living creatures have long been available, but most geologists have not provided similar guides for identifying rocks. To help fill this need I have prepared this brief handbook as an aid in identifying most of the common rocks of Indiana. It does not mention the rarer Indiana rock types. My purpose is to help the beginning student of rocks take his first steps into the subject with a little more confidence. I hope the satisfaction that he may get from being able to identify most rocks he is likely to find in Indiana may awaken in the student of natural history an interest in more serious study of rocks, minerals, and fossils.