Rocking and Rolling

The camp teacher has hired you as a detective to help Sam and Kate figure out what type of rock they have found.  The teacher would like to prove to the class which student is correct and why.  She has asked you to create a powerpoint for the students on different types of rocks.  She would like you to use an object that the students can relate to like food or an item that sixth graders would be familiar with to represent each type of rock.  Each type of rock should get its own page in your presentation. When your presentation is over, the students should be able to figure out who is right, Sam or Kate.