Book "Dig Into" Rock, Fossil, Geodes Books

These are a great little reference for kids of all ages!  Targeted to young children, fun illustrations and easy explanations make this a favorite reference for adults and children.  These are the first books I grab when I'm trying to describe a stone or fossil.  Basic explanations on general geology of rocks, crystals, geodes and fossils.  Please specify rocks, fossils or geode book