Planet Earth is made of rocks, from the tallest mountains to the deepest ocean floor. Every rock has a story to tell, and is continually changing. Planet Earth is already 4.5 billion years old. Every rock is telling the history of the Earth where we live on.
Geologists classify rocks in three groups: igneous, sedimentary, and metamorphic rocks. Equipped with the knowledge about classification of rocks, and field skills, you will be able to have a true collection of the most fundamental thing about Planet Earth: rocks.