List of rock types is an Android application developed by Helpful Books that serves as a comprehensive guide for petrologists. The app provides a list of all rock types recognized by petrologists, with no fixed number of specific types of rocks. It covers the unique combination of chemical composition, mineralogy, grain size, texture, or other distinguishing characteristics that can describe rock types. In addition, the app covers different classification systems that exist for each major type of rock, including sedimentary, metamorphic, and igneous. The app provides users with a detailed understanding of how to identify these rocks by their texture, streak, and location, among other factors.

The app is easy to use and navigate, with a clean and user-friendly interface. It is an excellent educational tool for petrologists, geologists, and students of earth sciences, providing an in-depth understanding of rock types. The app is free to use, making it accessible to anyone interested in learning about rocks. Overall, List of rock types is a must-have for those looking to expand their knowledge of geology and petrology.