Reading the Rocks
![Reading the Rocks](https://planetary.s3.amazonaws.com/web/assets/pictures/_576x760_crop_center-center_60_line/20140216_Planetary_Report_2004_v24n1.jpg 576w)
Gray hematite has been identified in three locations on Mars—Valles Marineris (background), Meridiani Planum (left), and Aram crater (bottom). Background: JPL/NASA; left: NASA/JPL/Arizona State University; center: John Betts Fine Minerals; bottom: Kees Veenenbos