California Rocks is a colorful quick identification guide to rocks and minerals in California. While accurate identification of rocks and minerals often requires extensive laboratory techniques, many are easily identified by unique combinations of features. This guide bases identification of rocks and minerals on color, hardness, crystal shape, and unique features. The rocks and minerals in this guide have been chosen specifically because they are either unique to California or commonly available and easily identified. The guide also provides brief descriptions of the different classes of rocks, differences between rocks and minerals, and accepted mineral groupings.