Lesson Summary In this lesson students complete the process of discovering the ingredients that make up a Mock Rock.  After observing the settled vials and predicting what the new ingredients are, students pour off the liquid from the top of the vial into anevaporation dish.  The liquid evaporates within 1 to 2 days, leaving behind crystal formations that give evidence for the final ingredients. Teacher Background Students will discover that the heavier particles settle near the bottom of the vial, while lighter particles settle in layers above that.  The children will discover a more gritty, sandy layer on the bottom.  Above that they will see more layers of smaller and smaller particles, including a silt layer and a flour layer.  The water on top will be dirty looking.  The learners pour off this top layer, which has dissolved ingredients.  When the liquid evaporates, the final ingredients (salt and alum) are discovered.  Each mineral has its own distinct crystal formation, making it fairly easy to identify. Set-up/Management Tips If evaporation dishes are not completely dry, you will need an alternative activity.  This is a good opportunity to have students read related non-fiction texts and/or to do a Read-Aloud activity. Literacy Support Books Available Through VAST Mediagraphies: (see Literacy Links) Word Wall/Word Bank The following words are key vocabulary words that will be introduced in this lesson and reinforced throughout the unit: crystal evaporate