Rocks: Hard, Soft, Smooth, and Rough
(Reklamlänk)
The rocks you see everyday can be grouped into different types, like igneous, sedimentary, or metamorphic. Some rocks are actually minerals, and you can even find fossils in some types of rocks.
(Reklamlänk)
The rocks you see everyday can be grouped into different types, like igneous, sedimentary, or metamorphic. Some rocks are actually minerals, and you can even find fossils in some types of rocks.
